PostgreSQL Source Code  git master
analyze.c File Reference
#include "postgres.h"
#include <math.h>
#include "access/detoast.h"
#include "access/genam.h"
#include "access/multixact.h"
#include "access/relation.h"
#include "access/sysattr.h"
#include "access/table.h"
#include "access/tableam.h"
#include "access/transam.h"
#include "access/tupconvert.h"
#include "access/visibilitymap.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/index.h"
#include "catalog/indexing.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_inherits.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_statistic_ext.h"
#include "commands/dbcommands.h"
#include "commands/progress.h"
#include "commands/tablecmds.h"
#include "commands/vacuum.h"
#include "executor/executor.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_oper.h"
#include "parser/parse_relation.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "statistics/extended_stats_internal.h"
#include "statistics/statistics.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "utils/acl.h"
#include "utils/attoptcache.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/pg_rusage.h"
#include "utils/sampling.h"
#include "utils/sortsupport.h"
#include "utils/spccache.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"
Include dependency graph for analyze.c:

Go to the source code of this file.

Data Structures

struct  AnlIndexData
 
struct  ScalarMCVItem
 
struct  CompareScalarsContext
 

Macros

#define WIDTH_THRESHOLD   1024
 
#define swapInt(a, b)   do {int _tmp; _tmp=a; a=b; b=_tmp;} while(0)
 
#define swapDatum(a, b)   do {Datum _tmp; _tmp=a; a=b; b=_tmp;} while(0)
 

Typedefs

typedef struct AnlIndexData AnlIndexData
 

Functions

static void do_analyze_rel (Relation onerel, VacuumParams *params, List *va_cols, AcquireSampleRowsFunc acquirefunc, BlockNumber relpages, bool inh, bool in_outer_xact, int elevel)
 
static void compute_index_stats (Relation onerel, double totalrows, AnlIndexData *indexdata, int nindexes, HeapTuple *rows, int numrows, MemoryContext col_context)
 
static VacAttrStatsexamine_attribute (Relation onerel, int attnum, Node *index_expr)
 
static int acquire_sample_rows (Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
 
static int compare_rows (const void *a, const void *b)
 
static int acquire_inherited_sample_rows (Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
 
static void update_attstats (Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
 
static Datum std_fetch_func (VacAttrStatsP stats, int rownum, bool *isNull)
 
static Datum ind_fetch_func (VacAttrStatsP stats, int rownum, bool *isNull)
 
void analyze_rel (Oid relid, RangeVar *relation, VacuumParams *params, List *va_cols, bool in_outer_xact, BufferAccessStrategy bstrategy)
 
static void compute_trivial_stats (VacAttrStatsP stats, AnalyzeAttrFetchFunc fetchfunc, int samplerows, double totalrows)
 
static void compute_distinct_stats (VacAttrStatsP stats, AnalyzeAttrFetchFunc fetchfunc, int samplerows, double totalrows)
 
static void compute_scalar_stats (VacAttrStatsP stats, AnalyzeAttrFetchFunc fetchfunc, int samplerows, double totalrows)
 
static int compare_scalars (const void *a, const void *b, void *arg)
 
static int compare_mcvs (const void *a, const void *b)
 
static int analyze_mcv_list (int *mcv_counts, int num_mcv, double stadistinct, double stanullfrac, int samplerows, double totalrows)
 
bool std_typanalyze (VacAttrStats *stats)
 

Variables

int default_statistics_target = 100
 
static MemoryContext anl_context = NULL
 
static BufferAccessStrategy vac_strategy
 

Macro Definition Documentation

◆ swapDatum

#define swapDatum (   a,
 
)    do {Datum _tmp; _tmp=a; a=b; b=_tmp;} while(0)

Definition at line 1813 of file analyze.c.

Referenced by compute_distinct_stats().

◆ swapInt

#define swapInt (   a,
 
)    do {int _tmp; _tmp=a; a=b; b=_tmp;} while(0)

Definition at line 1812 of file analyze.c.

Referenced by compute_distinct_stats().

◆ WIDTH_THRESHOLD

#define WIDTH_THRESHOLD   1024

Definition at line 1810 of file analyze.c.

Referenced by compute_distinct_stats(), and compute_scalar_stats().

Typedef Documentation

◆ AnlIndexData

typedef struct AnlIndexData AnlIndexData

Function Documentation

◆ acquire_inherited_sample_rows()

static int acquire_inherited_sample_rows ( Relation  onerel,
int  elevel,
HeapTuple rows,
int  targrows,
double *  totalrows,
double *  totaldeadrows 
)
static

Definition at line 1380 of file analyze.c.

References AccessShareLock, acquire_sample_rows(), FdwRoutine::AnalyzeForeignTable, Assert, CommandCounterIncrement(), convert_tuples_by_name(), elevel, equalTupleDescs(), ereport, errmsg(), execute_attr_map_tuple(), find_all_inheritors(), free_conversion_map(), get_namespace_name(), GetFdwRoutineForRelation(), heap_freetuple(), i, lfirst_oid, list_length(), Min, NoLock, palloc(), pgstat_progress_update_param(), PROGRESS_ANALYZE_CHILD_TABLES_DONE, PROGRESS_ANALYZE_CHILD_TABLES_TOTAL, PROGRESS_ANALYZE_CURRENT_CHILD_TABLE_RELID, RelationData::rd_rel, RELATION_IS_OTHER_TEMP, RelationGetDescr, RelationGetNamespace, RelationGetNumberOfBlocks, RelationGetRelationName, RelationGetRelid, SetRelationHasSubclass(), table_close(), and table_open().

Referenced by do_analyze_rel().

1383 {
1384  List *tableOIDs;
1385  Relation *rels;
1386  AcquireSampleRowsFunc *acquirefuncs;
1387  double *relblocks;
1388  double totalblocks;
1389  int numrows,
1390  nrels,
1391  i;
1392  ListCell *lc;
1393  bool has_child;
1394 
1395  /*
1396  * Find all members of inheritance set. We only need AccessShareLock on
1397  * the children.
1398  */
1399  tableOIDs =
1401 
1402  /*
1403  * Check that there's at least one descendant, else fail. This could
1404  * happen despite analyze_rel's relhassubclass check, if table once had a
1405  * child but no longer does. In that case, we can clear the
1406  * relhassubclass field so as not to make the same mistake again later.
1407  * (This is safe because we hold ShareUpdateExclusiveLock.)
1408  */
1409  if (list_length(tableOIDs) < 2)
1410  {
1411  /* CCI because we already updated the pg_class row in this command */
1413  SetRelationHasSubclass(RelationGetRelid(onerel), false);
1414  ereport(elevel,
1415  (errmsg("skipping analyze of \"%s.%s\" inheritance tree --- this inheritance tree contains no child tables",
1417  RelationGetRelationName(onerel))));
1418  return 0;
1419  }
1420 
1421  /*
1422  * Identify acquirefuncs to use, and count blocks in all the relations.
1423  * The result could overflow BlockNumber, so we use double arithmetic.
1424  */
1425  rels = (Relation *) palloc(list_length(tableOIDs) * sizeof(Relation));
1426  acquirefuncs = (AcquireSampleRowsFunc *)
1427  palloc(list_length(tableOIDs) * sizeof(AcquireSampleRowsFunc));
1428  relblocks = (double *) palloc(list_length(tableOIDs) * sizeof(double));
1429  totalblocks = 0;
1430  nrels = 0;
1431  has_child = false;
1432  foreach(lc, tableOIDs)
1433  {
1434  Oid childOID = lfirst_oid(lc);
1435  Relation childrel;
1436  AcquireSampleRowsFunc acquirefunc = NULL;
1437  BlockNumber relpages = 0;
1438 
1439  /* We already got the needed lock */
1440  childrel = table_open(childOID, NoLock);
1441 
1442  /* Ignore if temp table of another backend */
1443  if (RELATION_IS_OTHER_TEMP(childrel))
1444  {
1445  /* ... but release the lock on it */
1446  Assert(childrel != onerel);
1447  table_close(childrel, AccessShareLock);
1448  continue;
1449  }
1450 
1451  /* Check table type (MATVIEW can't happen, but might as well allow) */
1452  if (childrel->rd_rel->relkind == RELKIND_RELATION ||
1453  childrel->rd_rel->relkind == RELKIND_MATVIEW)
1454  {
1455  /* Regular table, so use the regular row acquisition function */
1456  acquirefunc = acquire_sample_rows;
1457  relpages = RelationGetNumberOfBlocks(childrel);
1458  }
1459  else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
1460  {
1461  /*
1462  * For a foreign table, call the FDW's hook function to see
1463  * whether it supports analysis.
1464  */
1465  FdwRoutine *fdwroutine;
1466  bool ok = false;
1467 
1468  fdwroutine = GetFdwRoutineForRelation(childrel, false);
1469 
1470  if (fdwroutine->AnalyzeForeignTable != NULL)
1471  ok = fdwroutine->AnalyzeForeignTable(childrel,
1472  &acquirefunc,
1473  &relpages);
1474 
1475  if (!ok)
1476  {
1477  /* ignore, but release the lock on it */
1478  Assert(childrel != onerel);
1479  table_close(childrel, AccessShareLock);
1480  continue;
1481  }
1482  }
1483  else
1484  {
1485  /*
1486  * ignore, but release the lock on it. don't try to unlock the
1487  * passed-in relation
1488  */
1489  Assert(childrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
1490  if (childrel != onerel)
1491  table_close(childrel, AccessShareLock);
1492  else
1493  table_close(childrel, NoLock);
1494  continue;
1495  }
1496 
1497  /* OK, we'll process this child */
1498  has_child = true;
1499  rels[nrels] = childrel;
1500  acquirefuncs[nrels] = acquirefunc;
1501  relblocks[nrels] = (double) relpages;
1502  totalblocks += (double) relpages;
1503  nrels++;
1504  }
1505 
1506  /*
1507  * If we don't have at least one child table to consider, fail. If the
1508  * relation is a partitioned table, it's not counted as a child table.
1509  */
1510  if (!has_child)
1511  {
1512  ereport(elevel,
1513  (errmsg("skipping analyze of \"%s.%s\" inheritance tree --- this inheritance tree contains no analyzable child tables",
1515  RelationGetRelationName(onerel))));
1516  return 0;
1517  }
1518 
1519  /*
1520  * Now sample rows from each relation, proportionally to its fraction of
1521  * the total block count. (This might be less than desirable if the child
1522  * rels have radically different free-space percentages, but it's not
1523  * clear that it's worth working harder.)
1524  */
1526  nrels);
1527  numrows = 0;
1528  *totalrows = 0;
1529  *totaldeadrows = 0;
1530  for (i = 0; i < nrels; i++)
1531  {
1532  Relation childrel = rels[i];
1533  AcquireSampleRowsFunc acquirefunc = acquirefuncs[i];
1534  double childblocks = relblocks[i];
1535 
1537  RelationGetRelid(childrel));
1538 
1539  if (childblocks > 0)
1540  {
1541  int childtargrows;
1542 
1543  childtargrows = (int) rint(targrows * childblocks / totalblocks);
1544  /* Make sure we don't overrun due to roundoff error */
1545  childtargrows = Min(childtargrows, targrows - numrows);
1546  if (childtargrows > 0)
1547  {
1548  int childrows;
1549  double trows,
1550  tdrows;
1551 
1552  /* Fetch a random sample of the child's rows */
1553  childrows = (*acquirefunc) (childrel, elevel,
1554  rows + numrows, childtargrows,
1555  &trows, &tdrows);
1556 
1557  /* We may need to convert from child's rowtype to parent's */
1558  if (childrows > 0 &&
1559  !equalTupleDescs(RelationGetDescr(childrel),
1560  RelationGetDescr(onerel)))
1561  {
1562  TupleConversionMap *map;
1563 
1564  map = convert_tuples_by_name(RelationGetDescr(childrel),
1565  RelationGetDescr(onerel));
1566  if (map != NULL)
1567  {
1568  int j;
1569 
1570  for (j = 0; j < childrows; j++)
1571  {
1572  HeapTuple newtup;
1573 
1574  newtup = execute_attr_map_tuple(rows[numrows + j], map);
1575  heap_freetuple(rows[numrows + j]);
1576  rows[numrows + j] = newtup;
1577  }
1578  free_conversion_map(map);
1579  }
1580  }
1581 
1582  /* And add to counts */
1583  numrows += childrows;
1584  *totalrows += trows;
1585  *totaldeadrows += tdrows;
1586  }
1587  }
1588 
1589  /*
1590  * Note: we cannot release the child-table locks, since we may have
1591  * pointers to their TOAST tables in the sampled rows.
1592  */
1593  table_close(childrel, NoLock);
1595  i + 1);
1596  }
1597 
1598  return numrows;
1599 }
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:167
#define RelationGetDescr(relation)
Definition: rel.h:503
AnalyzeForeignTable_function AnalyzeForeignTable
Definition: fdwapi.h:257
#define Min(x, y)
Definition: c.h:986
#define AccessShareLock
Definition: lockdefs.h:36
#define PROGRESS_ANALYZE_CURRENT_CHILD_TABLE_RELID
Definition: progress.h:45
uint32 BlockNumber
Definition: block.h:31
Form_pg_class rd_rel
Definition: rel.h:109
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
unsigned int Oid
Definition: postgres_ext.h:31
#define PROGRESS_ANALYZE_CHILD_TABLES_TOTAL
Definition: progress.h:43
void SetRelationHasSubclass(Oid relationId, bool relhassubclass)
Definition: tablecmds.c:3187
struct RelationData * Relation
Definition: relcache.h:26
TupleConversionMap * convert_tuples_by_name(TupleDesc indesc, TupleDesc outdesc)
Definition: tupconvert.c:102
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3316
#define NoLock
Definition: lockdefs.h:34
void free_conversion_map(TupleConversionMap *map)
Definition: tupconvert.c:284
#define RelationGetRelationName(relation)
Definition: rel.h:511
HeapTuple execute_attr_map_tuple(HeapTuple tuple, TupleConversionMap *map)
Definition: tupconvert.c:139
static int elevel
Definition: vacuumlazy.c:401
void CommandCounterIncrement(void)
Definition: xact.c:1022
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:212
#define ereport(elevel,...)
Definition: elog.h:157
#define Assert(condition)
Definition: c.h:804
void pgstat_progress_update_param(int index, int64 val)
#define RELATION_IS_OTHER_TEMP(relation)
Definition: rel.h:631
#define PROGRESS_ANALYZE_CHILD_TABLES_DONE
Definition: progress.h:44
static int list_length(const List *l)
Definition: pg_list.h:149
int(* AcquireSampleRowsFunc)(Relation relation, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
Definition: fdwapi.h:151
List * find_all_inheritors(Oid parentrelId, LOCKMODE lockmode, List **numparents)
Definition: pg_inherits.c:256
void * palloc(Size size)
Definition: mcxt.c:1062
int errmsg(const char *fmt,...)
Definition: elog.c:909
FdwRoutine * GetFdwRoutineForRelation(Relation relation, bool makecopy)
Definition: foreign.c:427
int i
bool equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
Definition: tupdesc.c:402
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:39
Definition: pg_list.h:50
#define RelationGetRelid(relation)
Definition: rel.h:477
#define lfirst_oid(lc)
Definition: pg_list.h:171
static int acquire_sample_rows(Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
Definition: analyze.c:1134
#define RelationGetNamespace(relation)
Definition: rel.h:518

◆ acquire_sample_rows()

static int acquire_sample_rows ( Relation  onerel,
int  elevel,
HeapTuple rows,
int  targrows,
double *  totalrows,
double *  totaldeadrows 
)
static

Definition at line 1134 of file analyze.c.

References Assert, BlockSampler_HasMore(), BlockSampler_Init(), BlockSampler_Next(), compare_rows(), ereport, errmsg(), ExecCopySlotHeapTuple(), ExecDropSingleTupleTableSlot(), get_tablespace_maintenance_io_concurrency(), GetOldestNonRemovableTransactionId(), heap_freetuple(), i, InvalidBlockNumber, BlockSamplerData::m, MAIN_FORKNUM, pgstat_progress_update_param(), PrefetchBuffer(), PROGRESS_ANALYZE_BLOCKS_DONE, PROGRESS_ANALYZE_BLOCKS_TOTAL, qsort, random(), ReservoirStateData::randstate, RelationData::rd_rel, RelationGetNumberOfBlocks, RelationGetRelationName, reservoir_get_next_S(), reservoir_init_selection_state(), TableScanDescData::rs_rd, sampler_random_fract(), table_beginscan_analyze(), table_endscan(), table_scan_analyze_next_block(), table_scan_analyze_next_tuple(), table_slot_create(), and vacuum_delay_point().

Referenced by acquire_inherited_sample_rows(), and analyze_rel().

1137 {
1138  int numrows = 0; /* # rows now in reservoir */
1139  double samplerows = 0; /* total # rows collected */
1140  double liverows = 0; /* # live rows seen */
1141  double deadrows = 0; /* # dead rows seen */
1142  double rowstoskip = -1; /* -1 means not set yet */
1143  long randseed; /* Seed for block sampler(s) */
1144  BlockNumber totalblocks;
1145  TransactionId OldestXmin;
1146  BlockSamplerData bs;
1147  ReservoirStateData rstate;
1148  TupleTableSlot *slot;
1149  TableScanDesc scan;
1150  BlockNumber nblocks;
1151  BlockNumber blksdone = 0;
1152 #ifdef USE_PREFETCH
1153  int prefetch_maximum = 0; /* blocks to prefetch if enabled */
1154  BlockSamplerData prefetch_bs;
1155 #endif
1156 
1157  Assert(targrows > 0);
1158 
1159  totalblocks = RelationGetNumberOfBlocks(onerel);
1160 
1161  /* Need a cutoff xmin for HeapTupleSatisfiesVacuum */
1162  OldestXmin = GetOldestNonRemovableTransactionId(onerel);
1163 
1164  /* Prepare for sampling block numbers */
1165  randseed = random();
1166  nblocks = BlockSampler_Init(&bs, totalblocks, targrows, randseed);
1167 
1168 #ifdef USE_PREFETCH
1169  prefetch_maximum = get_tablespace_maintenance_io_concurrency(onerel->rd_rel->reltablespace);
1170  /* Create another BlockSampler, using the same seed, for prefetching */
1171  if (prefetch_maximum)
1172  (void) BlockSampler_Init(&prefetch_bs, totalblocks, targrows, randseed);
1173 #endif
1174 
1175  /* Report sampling block numbers */
1177  nblocks);
1178 
1179  /* Prepare for sampling rows */
1180  reservoir_init_selection_state(&rstate, targrows);
1181 
1182  scan = table_beginscan_analyze(onerel);
1183  slot = table_slot_create(onerel, NULL);
1184 
1185 #ifdef USE_PREFETCH
1186 
1187  /*
1188  * If we are doing prefetching, then go ahead and tell the kernel about
1189  * the first set of pages we are going to want. This also moves our
1190  * iterator out ahead of the main one being used, where we will keep it so
1191  * that we're always pre-fetching out prefetch_maximum number of blocks
1192  * ahead.
1193  */
1194  if (prefetch_maximum)
1195  {
1196  for (int i = 0; i < prefetch_maximum; i++)
1197  {
1198  BlockNumber prefetch_block;
1199 
1200  if (!BlockSampler_HasMore(&prefetch_bs))
1201  break;
1202 
1203  prefetch_block = BlockSampler_Next(&prefetch_bs);
1204  PrefetchBuffer(scan->rs_rd, MAIN_FORKNUM, prefetch_block);
1205  }
1206  }
1207 #endif
1208 
1209  /* Outer loop over blocks to sample */
1210  while (BlockSampler_HasMore(&bs))
1211  {
1212  bool block_accepted;
1213  BlockNumber targblock = BlockSampler_Next(&bs);
1214 #ifdef USE_PREFETCH
1215  BlockNumber prefetch_targblock = InvalidBlockNumber;
1216 
1217  /*
1218  * Make sure that every time the main BlockSampler is moved forward
1219  * that our prefetch BlockSampler also gets moved forward, so that we
1220  * always stay out ahead.
1221  */
1222  if (prefetch_maximum && BlockSampler_HasMore(&prefetch_bs))
1223  prefetch_targblock = BlockSampler_Next(&prefetch_bs);
1224 #endif
1225 
1227 
1228  block_accepted = table_scan_analyze_next_block(scan, targblock, vac_strategy);
1229 
1230 #ifdef USE_PREFETCH
1231 
1232  /*
1233  * When pre-fetching, after we get a block, tell the kernel about the
1234  * next one we will want, if there's any left.
1235  *
1236  * We want to do this even if the table_scan_analyze_next_block() call
1237  * above decides against analyzing the block it picked.
1238  */
1239  if (prefetch_maximum && prefetch_targblock != InvalidBlockNumber)
1240  PrefetchBuffer(scan->rs_rd, MAIN_FORKNUM, prefetch_targblock);
1241 #endif
1242 
1243  /*
1244  * Don't analyze if table_scan_analyze_next_block() indicated this
1245  * block is unsuitable for analyzing.
1246  */
1247  if (!block_accepted)
1248  continue;
1249 
1250  while (table_scan_analyze_next_tuple(scan, OldestXmin, &liverows, &deadrows, slot))
1251  {
1252  /*
1253  * The first targrows sample rows are simply copied into the
1254  * reservoir. Then we start replacing tuples in the sample until
1255  * we reach the end of the relation. This algorithm is from Jeff
1256  * Vitter's paper (see full citation in utils/misc/sampling.c). It
1257  * works by repeatedly computing the number of tuples to skip
1258  * before selecting a tuple, which replaces a randomly chosen
1259  * element of the reservoir (current set of tuples). At all times
1260  * the reservoir is a true random sample of the tuples we've
1261  * passed over so far, so when we fall off the end of the relation
1262  * we're done.
1263  */
1264  if (numrows < targrows)
1265  rows[numrows++] = ExecCopySlotHeapTuple(slot);
1266  else
1267  {
1268  /*
1269  * t in Vitter's paper is the number of records already
1270  * processed. If we need to compute a new S value, we must
1271  * use the not-yet-incremented value of samplerows as t.
1272  */
1273  if (rowstoskip < 0)
1274  rowstoskip = reservoir_get_next_S(&rstate, samplerows, targrows);
1275 
1276  if (rowstoskip <= 0)
1277  {
1278  /*
1279  * Found a suitable tuple, so save it, replacing one old
1280  * tuple at random
1281  */
1282  int k = (int) (targrows * sampler_random_fract(rstate.randstate));
1283 
1284  Assert(k >= 0 && k < targrows);
1285  heap_freetuple(rows[k]);
1286  rows[k] = ExecCopySlotHeapTuple(slot);
1287  }
1288 
1289  rowstoskip -= 1;
1290  }
1291 
1292  samplerows += 1;
1293  }
1294 
1296  ++blksdone);
1297  }
1298 
1300  table_endscan(scan);
1301 
1302  /*
1303  * If we didn't find as many tuples as we wanted then we're done. No sort
1304  * is needed, since they're already in order.
1305  *
1306  * Otherwise we need to sort the collected tuples by position
1307  * (itempointer). It's not worth worrying about corner cases where the
1308  * tuples are already sorted.
1309  */
1310  if (numrows == targrows)
1311  qsort((void *) rows, numrows, sizeof(HeapTuple), compare_rows);
1312 
1313  /*
1314  * Estimate total numbers of live and dead rows in relation, extrapolating
1315  * on the assumption that the average tuple density in pages we didn't
1316  * scan is the same as in the pages we did scan. Since what we scanned is
1317  * a random sample of the pages in the relation, this should be a good
1318  * assumption.
1319  */
1320  if (bs.m > 0)
1321  {
1322  *totalrows = floor((liverows / bs.m) * totalblocks + 0.5);
1323  *totaldeadrows = floor((deadrows / bs.m) * totalblocks + 0.5);
1324  }
1325  else
1326  {
1327  *totalrows = 0.0;
1328  *totaldeadrows = 0.0;
1329  }
1330 
1331  /*
1332  * Emit some interesting relation info
1333  */
1334  ereport(elevel,
1335  (errmsg("\"%s\": scanned %d of %u pages, "
1336  "containing %.0f live rows and %.0f dead rows; "
1337  "%d rows in sample, %.0f estimated total rows",
1338  RelationGetRelationName(onerel),
1339  bs.m, totalblocks,
1340  liverows, deadrows,
1341  numrows, *totalrows)));
1342 
1343  return numrows;
1344 }
TupleTableSlot * table_slot_create(Relation relation, List **reglist)
Definition: tableam.c:91
bool BlockSampler_HasMore(BlockSampler bs)
Definition: sampling.c:58
#define PROGRESS_ANALYZE_BLOCKS_TOTAL
Definition: progress.h:39
uint32 TransactionId
Definition: c.h:587
BlockNumber BlockSampler_Next(BlockSampler bs)
Definition: sampling.c:64
long random(void)
Definition: random.c:22
double sampler_random_fract(SamplerRandomState randstate)
Definition: sampling.c:242
static BufferAccessStrategy vac_strategy
Definition: analyze.c:86
uint32 BlockNumber
Definition: block.h:31
void reservoir_init_selection_state(ReservoirState rs, int n)
Definition: sampling.c:133
Form_pg_class rd_rel
Definition: rel.h:109
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
int get_tablespace_maintenance_io_concurrency(Oid spcid)
Definition: spccache.c:228
static bool table_scan_analyze_next_block(TableScanDesc scan, BlockNumber blockno, BufferAccessStrategy bstrategy)
Definition: tableam.h:1690
TransactionId GetOldestNonRemovableTransactionId(Relation rel)
Definition: procarray.c:2005
void ExecDropSingleTupleTableSlot(TupleTableSlot *slot)
Definition: execTuples.c:1254
#define PROGRESS_ANALYZE_BLOCKS_DONE
Definition: progress.h:40
#define RelationGetRelationName(relation)
Definition: rel.h:511
static int compare_rows(const void *a, const void *b)
Definition: analyze.c:1350
BlockNumber BlockSampler_Init(BlockSampler bs, BlockNumber nblocks, int samplesize, long randseed)
Definition: sampling.c:39
static int elevel
Definition: vacuumlazy.c:401
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:212
#define ereport(elevel,...)
Definition: elog.h:157
static HeapTuple ExecCopySlotHeapTuple(TupleTableSlot *slot)
Definition: tuptable.h:452
#define Assert(condition)
Definition: c.h:804
void pgstat_progress_update_param(int index, int64 val)
static bool table_scan_analyze_next_tuple(TableScanDesc scan, TransactionId OldestXmin, double *liverows, double *deadrows, TupleTableSlot *slot)
Definition: tableam.h:1708
#define InvalidBlockNumber
Definition: block.h:33
Relation rs_rd
Definition: relscan.h:34
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:991
int errmsg(const char *fmt,...)
Definition: elog.c:909
int i
PrefetchBufferResult PrefetchBuffer(Relation reln, ForkNumber forkNum, BlockNumber blockNum)
Definition: bufmgr.c:587
#define qsort(a, b, c, d)
Definition: port.h:505
void vacuum_delay_point(void)
Definition: vacuum.c:2149
SamplerRandomState randstate
Definition: sampling.h:50
double reservoir_get_next_S(ReservoirState rs, double t, int n)
Definition: sampling.c:146
static TableScanDesc table_beginscan_analyze(Relation rel)
Definition: tableam.h:980

◆ analyze_mcv_list()

static int analyze_mcv_list ( int *  mcv_counts,
int  num_mcv,
double  stadistinct,
double  stanullfrac,
int  samplerows,
double  totalrows 
)
static

Definition at line 2948 of file analyze.c.

References i, and K.

Referenced by compute_distinct_stats(), and compute_scalar_stats().

2954 {
2955  double ndistinct_table;
2956  double sumcount;
2957  int i;
2958 
2959  /*
2960  * If the entire table was sampled, keep the whole list. This also
2961  * protects us against division by zero in the code below.
2962  */
2963  if (samplerows == totalrows || totalrows <= 1.0)
2964  return num_mcv;
2965 
2966  /* Re-extract the estimated number of distinct nonnull values in table */
2967  ndistinct_table = stadistinct;
2968  if (ndistinct_table < 0)
2969  ndistinct_table = -ndistinct_table * totalrows;
2970 
2971  /*
2972  * Exclude the least common values from the MCV list, if they are not
2973  * significantly more common than the estimated selectivity they would
2974  * have if they weren't in the list. All non-MCV values are assumed to be
2975  * equally common, after taking into account the frequencies of all the
2976  * values in the MCV list and the number of nulls (c.f. eqsel()).
2977  *
2978  * Here sumcount tracks the total count of all but the last (least common)
2979  * value in the MCV list, allowing us to determine the effect of excluding
2980  * that value from the list.
2981  *
2982  * Note that we deliberately do this by removing values from the full
2983  * list, rather than starting with an empty list and adding values,
2984  * because the latter approach can fail to add any values if all the most
2985  * common values have around the same frequency and make up the majority
2986  * of the table, so that the overall average frequency of all values is
2987  * roughly the same as that of the common values. This would lead to any
2988  * uncommon values being significantly overestimated.
2989  */
2990  sumcount = 0.0;
2991  for (i = 0; i < num_mcv - 1; i++)
2992  sumcount += mcv_counts[i];
2993 
2994  while (num_mcv > 0)
2995  {
2996  double selec,
2997  otherdistinct,
2998  N,
2999  n,
3000  K,
3001  variance,
3002  stddev;
3003 
3004  /*
3005  * Estimated selectivity the least common value would have if it
3006  * wasn't in the MCV list (c.f. eqsel()).
3007  */
3008  selec = 1.0 - sumcount / samplerows - stanullfrac;
3009  if (selec < 0.0)
3010  selec = 0.0;
3011  if (selec > 1.0)
3012  selec = 1.0;
3013  otherdistinct = ndistinct_table - (num_mcv - 1);
3014  if (otherdistinct > 1)
3015  selec /= otherdistinct;
3016 
3017  /*
3018  * If the value is kept in the MCV list, its population frequency is
3019  * assumed to equal its sample frequency. We use the lower end of a
3020  * textbook continuity-corrected Wald-type confidence interval to
3021  * determine if that is significantly more common than the non-MCV
3022  * frequency --- specifically we assume the population frequency is
3023  * highly likely to be within around 2 standard errors of the sample
3024  * frequency, which equates to an interval of 2 standard deviations
3025  * either side of the sample count, plus an additional 0.5 for the
3026  * continuity correction. Since we are sampling without replacement,
3027  * this is a hypergeometric distribution.
3028  *
3029  * XXX: Empirically, this approach seems to work quite well, but it
3030  * may be worth considering more advanced techniques for estimating
3031  * the confidence interval of the hypergeometric distribution.
3032  */
3033  N = totalrows;
3034  n = samplerows;
3035  K = N * mcv_counts[num_mcv - 1] / n;
3036  variance = n * K * (N - K) * (N - n) / (N * N * (N - 1));
3037  stddev = sqrt(variance);
3038 
3039  if (mcv_counts[num_mcv - 1] > selec * samplerows + 2 * stddev + 0.5)
3040  {
3041  /*
3042  * The value is significantly more common than the non-MCV
3043  * selectivity would suggest. Keep it, and all the other more
3044  * common values in the list.
3045  */
3046  break;
3047  }
3048  else
3049  {
3050  /* Discard this value and consider the next least common value */
3051  num_mcv--;
3052  if (num_mcv == 0)
3053  break;
3054  sumcount -= mcv_counts[num_mcv - 1];
3055  }
3056  }
3057  return num_mcv;
3058 }
#define K(t)
Definition: sha1.c:66
int i

◆ analyze_rel()

void analyze_rel ( Oid  relid,
RangeVar relation,
VacuumParams params,
List va_cols,
bool  in_outer_xact,
BufferAccessStrategy  bstrategy 
)

Definition at line 120 of file analyze.c.

References acquire_sample_rows(), FdwRoutine::AnalyzeForeignTable, CHECK_FOR_INTERRUPTS, DEBUG2, do_analyze_rel(), elevel, ereport, errmsg(), GetFdwRoutineForRelation(), INFO, VacuumParams::log_min_duration, NoLock, VacuumParams::options, pgstat_progress_end_command(), pgstat_progress_start_command(), PROGRESS_COMMAND_ANALYZE, RelationData::rd_rel, relation_close(), RELATION_IS_OTHER_TEMP, RelationGetNumberOfBlocks, RelationGetRelationName, RelationGetRelid, ShareUpdateExclusiveLock, VACOPT_ANALYZE, VACOPT_VACUUM, VACOPT_VERBOSE, vacuum_is_relation_owner(), vacuum_open_relation(), and WARNING.

Referenced by vacuum().

123 {
124  Relation onerel;
125  int elevel;
126  AcquireSampleRowsFunc acquirefunc = NULL;
127  BlockNumber relpages = 0;
128 
129  /* Select logging level */
130  if (params->options & VACOPT_VERBOSE)
131  elevel = INFO;
132  else
133  elevel = DEBUG2;
134 
135  /* Set up static variables */
136  vac_strategy = bstrategy;
137 
138  /*
139  * Check for user-requested abort.
140  */
142 
143  /*
144  * Open the relation, getting ShareUpdateExclusiveLock to ensure that two
145  * ANALYZEs don't run on it concurrently. (This also locks out a
146  * concurrent VACUUM, which doesn't matter much at the moment but might
147  * matter if we ever try to accumulate stats on dead tuples.) If the rel
148  * has been dropped since we last saw it, we don't need to process it.
149  *
150  * Make sure to generate only logs for ANALYZE in this case.
151  */
152  onerel = vacuum_open_relation(relid, relation, params->options & ~(VACOPT_VACUUM),
153  params->log_min_duration >= 0,
155 
156  /* leave if relation could not be opened or locked */
157  if (!onerel)
158  return;
159 
160  /*
161  * Check if relation needs to be skipped based on ownership. This check
162  * happens also when building the relation list to analyze for a manual
163  * operation, and needs to be done additionally here as ANALYZE could
164  * happen across multiple transactions where relation ownership could have
165  * changed in-between. Make sure to generate only logs for ANALYZE in
166  * this case.
167  */
169  onerel->rd_rel,
170  params->options & VACOPT_ANALYZE))
171  {
173  return;
174  }
175 
176  /*
177  * Silently ignore tables that are temp tables of other backends ---
178  * trying to analyze these is rather pointless, since their contents are
179  * probably not up-to-date on disk. (We don't throw a warning here; it
180  * would just lead to chatter during a database-wide ANALYZE.)
181  */
182  if (RELATION_IS_OTHER_TEMP(onerel))
183  {
185  return;
186  }
187 
188  /*
189  * We can ANALYZE any table except pg_statistic. See update_attstats
190  */
191  if (RelationGetRelid(onerel) == StatisticRelationId)
192  {
194  return;
195  }
196 
197  /*
198  * Check that it's of an analyzable relkind, and set up appropriately.
199  */
200  if (onerel->rd_rel->relkind == RELKIND_RELATION ||
201  onerel->rd_rel->relkind == RELKIND_MATVIEW)
202  {
203  /* Regular table, so we'll use the regular row acquisition function */
204  acquirefunc = acquire_sample_rows;
205  /* Also get regular table's size */
206  relpages = RelationGetNumberOfBlocks(onerel);
207  }
208  else if (onerel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
209  {
210  /*
211  * For a foreign table, call the FDW's hook function to see whether it
212  * supports analysis.
213  */
214  FdwRoutine *fdwroutine;
215  bool ok = false;
216 
217  fdwroutine = GetFdwRoutineForRelation(onerel, false);
218 
219  if (fdwroutine->AnalyzeForeignTable != NULL)
220  ok = fdwroutine->AnalyzeForeignTable(onerel,
221  &acquirefunc,
222  &relpages);
223 
224  if (!ok)
225  {
227  (errmsg("skipping \"%s\" --- cannot analyze this foreign table",
228  RelationGetRelationName(onerel))));
230  return;
231  }
232  }
233  else if (onerel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
234  {
235  /*
236  * For partitioned tables, we want to do the recursive ANALYZE below.
237  */
238  }
239  else
240  {
241  /* No need for a WARNING if we already complained during VACUUM */
242  if (!(params->options & VACOPT_VACUUM))
244  (errmsg("skipping \"%s\" --- cannot analyze non-tables or special system tables",
245  RelationGetRelationName(onerel))));
247  return;
248  }
249 
250  /*
251  * OK, let's do it. First, initialize progress reporting.
252  */
254  RelationGetRelid(onerel));
255 
256  /*
257  * Do the normal non-recursive ANALYZE. We can skip this for partitioned
258  * tables, which don't contain any rows.
259  */
260  if (onerel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
261  do_analyze_rel(onerel, params, va_cols, acquirefunc,
262  relpages, false, in_outer_xact, elevel);
263 
264  /*
265  * If there are child tables, do recursive ANALYZE.
266  */
267  if (onerel->rd_rel->relhassubclass)
268  do_analyze_rel(onerel, params, va_cols, acquirefunc, relpages,
269  true, in_outer_xact, elevel);
270 
271  /*
272  * Close source relation now, but keep lock so that no one deletes it
273  * before we commit. (If someone did, they'd fail to clean up the entries
274  * we made in pg_statistic. Also, releasing the lock before commit would
275  * expose us to concurrent-update failures in update_attstats.)
276  */
277  relation_close(onerel, NoLock);
278 
280 }
static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, AcquireSampleRowsFunc acquirefunc, BlockNumber relpages, bool inh, bool in_outer_xact, int elevel)
Definition: analyze.c:290
AnalyzeForeignTable_function AnalyzeForeignTable
Definition: fdwapi.h:257
#define VACOPT_ANALYZE
Definition: vacuum.h:179
#define INFO
Definition: elog.h:33
static BufferAccessStrategy vac_strategy
Definition: analyze.c:86
uint32 BlockNumber
Definition: block.h:31
Form_pg_class rd_rel
Definition: rel.h:109
void pgstat_progress_end_command(void)
bits32 options
Definition: vacuum.h:211
#define DEBUG2
Definition: elog.h:24
void pgstat_progress_start_command(ProgressCommandType cmdtype, Oid relid)
#define NoLock
Definition: lockdefs.h:34
#define RelationGetRelationName(relation)
Definition: rel.h:511
#define WARNING
Definition: elog.h:40
static int elevel
Definition: vacuumlazy.c:401
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:212
#define ereport(elevel,...)
Definition: elog.h:157
#define ShareUpdateExclusiveLock
Definition: lockdefs.h:39
void relation_close(Relation relation, LOCKMODE lockmode)
Definition: relation.c:206
#define VACOPT_VACUUM
Definition: vacuum.h:178
#define RELATION_IS_OTHER_TEMP(relation)
Definition: rel.h:631
int log_min_duration
Definition: vacuum.h:219
#define VACOPT_VERBOSE
Definition: vacuum.h:180
int(* AcquireSampleRowsFunc)(Relation relation, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
Definition: fdwapi.h:151
int errmsg(const char *fmt,...)
Definition: elog.c:909
FdwRoutine * GetFdwRoutineForRelation(Relation relation, bool makecopy)
Definition: foreign.c:427
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:120
Relation vacuum_open_relation(Oid relid, RangeVar *relation, bits32 options, bool verbose, LOCKMODE lmode)
Definition: vacuum.c:633
bool vacuum_is_relation_owner(Oid relid, Form_pg_class reltuple, bits32 options)
Definition: vacuum.c:559
#define RelationGetRelid(relation)
Definition: rel.h:477
static int acquire_sample_rows(Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
Definition: analyze.c:1134

◆ compare_mcvs()

static int compare_mcvs ( const void *  a,
const void *  b 
)
static

Definition at line 2930 of file analyze.c.

Referenced by compute_scalar_stats().

2931 {
2932  int da = ((const ScalarMCVItem *) a)->first;
2933  int db = ((const ScalarMCVItem *) b)->first;
2934 
2935  return da - db;
2936 }

◆ compare_rows()

static int compare_rows ( const void *  a,
const void *  b 
)
static

Definition at line 1350 of file analyze.c.

References ItemPointerGetBlockNumber, ItemPointerGetOffsetNumber, and HeapTupleData::t_self.

Referenced by acquire_sample_rows().

1351 {
1352  HeapTuple ha = *(const HeapTuple *) a;
1353  HeapTuple hb = *(const HeapTuple *) b;
1358 
1359  if (ba < bb)
1360  return -1;
1361  if (ba > bb)
1362  return 1;
1363  if (oa < ob)
1364  return -1;
1365  if (oa > ob)
1366  return 1;
1367  return 0;
1368 }
uint32 BlockNumber
Definition: block.h:31
uint16 OffsetNumber
Definition: off.h:24
ItemPointerData t_self
Definition: htup.h:65
#define ItemPointerGetOffsetNumber(pointer)
Definition: itemptr.h:117
#define ItemPointerGetBlockNumber(pointer)
Definition: itemptr.h:98

◆ compare_scalars()

static int compare_scalars ( const void *  a,
const void *  b,
void *  arg 
)
static

Definition at line 2899 of file analyze.c.

References ApplySortComparator(), compare(), CompareScalarsContext::ssup, and CompareScalarsContext::tupnoLink.

Referenced by compute_scalar_stats().

2900 {
2901  Datum da = ((const ScalarItem *) a)->value;
2902  int ta = ((const ScalarItem *) a)->tupno;
2903  Datum db = ((const ScalarItem *) b)->value;
2904  int tb = ((const ScalarItem *) b)->tupno;
2906  int compare;
2907 
2908  compare = ApplySortComparator(da, false, db, false, cxt->ssup);
2909  if (compare != 0)
2910  return compare;
2911 
2912  /*
2913  * The two datums are equal, so update cxt->tupnoLink[].
2914  */
2915  if (cxt->tupnoLink[ta] < tb)
2916  cxt->tupnoLink[ta] = tb;
2917  if (cxt->tupnoLink[tb] < ta)
2918  cxt->tupnoLink[tb] = ta;
2919 
2920  /*
2921  * For equal datums, sort by tupno
2922  */
2923  return ta - tb;
2924 }
static int compare(const void *arg1, const void *arg2)
Definition: geqo_pool.c:145
SortSupport ssup
Definition: analyze.c:1826
uintptr_t Datum
Definition: postgres.h:411
void * arg
static int ApplySortComparator(Datum datum1, bool isNull1, Datum datum2, bool isNull2, SortSupport ssup)
Definition: sortsupport.h:200

◆ compute_distinct_stats()

static void compute_distinct_stats ( VacAttrStatsP  stats,
AnalyzeAttrFetchFunc  fetchfunc,
int  samplerows,
double  totalrows 
)
static

Definition at line 2027 of file analyze.c.

References analyze_mcv_list(), VacAttrStats::anl_context, VacAttrStats::attr, VacAttrStats::attrcollid, VacAttrStats::attrtype, datumCopy(), DatumGetBool, DatumGetCString, DatumGetPointer, StdAnalyzeData::eqfunc, StdAnalyzeData::eqopr, VacAttrStats::extra_data, f1, fmgr_info(), FunctionCall2Coll(), i, MemoryContextSwitchTo(), VacAttrStats::numnumbers, VacAttrStats::numvalues, palloc(), PG_DETOAST_DATUM, PointerGetDatum, VacAttrStats::stacoll, VacAttrStats::stadistinct, VacAttrStats::stakind, VacAttrStats::stanullfrac, VacAttrStats::stanumbers, VacAttrStats::staop, VacAttrStats::stats_valid, VacAttrStats::stavalues, VacAttrStats::stawidth, swapDatum, swapInt, toast_raw_datum_size(), vacuum_delay_point(), value, VARSIZE_ANY, and WIDTH_THRESHOLD.

Referenced by std_typanalyze().

2031 {
2032  int i;
2033  int null_cnt = 0;
2034  int nonnull_cnt = 0;
2035  int toowide_cnt = 0;
2036  double total_width = 0;
2037  bool is_varlena = (!stats->attrtype->typbyval &&
2038  stats->attrtype->typlen == -1);
2039  bool is_varwidth = (!stats->attrtype->typbyval &&
2040  stats->attrtype->typlen < 0);
2041  FmgrInfo f_cmpeq;
2042  typedef struct
2043  {
2044  Datum value;
2045  int count;
2046  } TrackItem;
2047  TrackItem *track;
2048  int track_cnt,
2049  track_max;
2050  int num_mcv = stats->attr->attstattarget;
2051  StdAnalyzeData *mystats = (StdAnalyzeData *) stats->extra_data;
2052 
2053  /*
2054  * We track up to 2*n values for an n-element MCV list; but at least 10
2055  */
2056  track_max = 2 * num_mcv;
2057  if (track_max < 10)
2058  track_max = 10;
2059  track = (TrackItem *) palloc(track_max * sizeof(TrackItem));
2060  track_cnt = 0;
2061 
2062  fmgr_info(mystats->eqfunc, &f_cmpeq);
2063 
2064  for (i = 0; i < samplerows; i++)
2065  {
2066  Datum value;
2067  bool isnull;
2068  bool match;
2069  int firstcount1,
2070  j;
2071 
2073 
2074  value = fetchfunc(stats, i, &isnull);
2075 
2076  /* Check for null/nonnull */
2077  if (isnull)
2078  {
2079  null_cnt++;
2080  continue;
2081  }
2082  nonnull_cnt++;
2083 
2084  /*
2085  * If it's a variable-width field, add up widths for average width
2086  * calculation. Note that if the value is toasted, we use the toasted
2087  * width. We don't bother with this calculation if it's a fixed-width
2088  * type.
2089  */
2090  if (is_varlena)
2091  {
2092  total_width += VARSIZE_ANY(DatumGetPointer(value));
2093 
2094  /*
2095  * If the value is toasted, we want to detoast it just once to
2096  * avoid repeated detoastings and resultant excess memory usage
2097  * during the comparisons. Also, check to see if the value is
2098  * excessively wide, and if so don't detoast at all --- just
2099  * ignore the value.
2100  */
2102  {
2103  toowide_cnt++;
2104  continue;
2105  }
2106  value = PointerGetDatum(PG_DETOAST_DATUM(value));
2107  }
2108  else if (is_varwidth)
2109  {
2110  /* must be cstring */
2111  total_width += strlen(DatumGetCString(value)) + 1;
2112  }
2113 
2114  /*
2115  * See if the value matches anything we're already tracking.
2116  */
2117  match = false;
2118  firstcount1 = track_cnt;
2119  for (j = 0; j < track_cnt; j++)
2120  {
2121  if (DatumGetBool(FunctionCall2Coll(&f_cmpeq,
2122  stats->attrcollid,
2123  value, track[j].value)))
2124  {
2125  match = true;
2126  break;
2127  }
2128  if (j < firstcount1 && track[j].count == 1)
2129  firstcount1 = j;
2130  }
2131 
2132  if (match)
2133  {
2134  /* Found a match */
2135  track[j].count++;
2136  /* This value may now need to "bubble up" in the track list */
2137  while (j > 0 && track[j].count > track[j - 1].count)
2138  {
2139  swapDatum(track[j].value, track[j - 1].value);
2140  swapInt(track[j].count, track[j - 1].count);
2141  j--;
2142  }
2143  }
2144  else
2145  {
2146  /* No match. Insert at head of count-1 list */
2147  if (track_cnt < track_max)
2148  track_cnt++;
2149  for (j = track_cnt - 1; j > firstcount1; j--)
2150  {
2151  track[j].value = track[j - 1].value;
2152  track[j].count = track[j - 1].count;
2153  }
2154  if (firstcount1 < track_cnt)
2155  {
2156  track[firstcount1].value = value;
2157  track[firstcount1].count = 1;
2158  }
2159  }
2160  }
2161 
2162  /* We can only compute real stats if we found some non-null values. */
2163  if (nonnull_cnt > 0)
2164  {
2165  int nmultiple,
2166  summultiple;
2167 
2168  stats->stats_valid = true;
2169  /* Do the simple null-frac and width stats */
2170  stats->stanullfrac = (double) null_cnt / (double) samplerows;
2171  if (is_varwidth)
2172  stats->stawidth = total_width / (double) nonnull_cnt;
2173  else
2174  stats->stawidth = stats->attrtype->typlen;
2175 
2176  /* Count the number of values we found multiple times */
2177  summultiple = 0;
2178  for (nmultiple = 0; nmultiple < track_cnt; nmultiple++)
2179  {
2180  if (track[nmultiple].count == 1)
2181  break;
2182  summultiple += track[nmultiple].count;
2183  }
2184 
2185  if (nmultiple == 0)
2186  {
2187  /*
2188  * If we found no repeated non-null values, assume it's a unique
2189  * column; but be sure to discount for any nulls we found.
2190  */
2191  stats->stadistinct = -1.0 * (1.0 - stats->stanullfrac);
2192  }
2193  else if (track_cnt < track_max && toowide_cnt == 0 &&
2194  nmultiple == track_cnt)
2195  {
2196  /*
2197  * Our track list includes every value in the sample, and every
2198  * value appeared more than once. Assume the column has just
2199  * these values. (This case is meant to address columns with
2200  * small, fixed sets of possible values, such as boolean or enum
2201  * columns. If there are any values that appear just once in the
2202  * sample, including too-wide values, we should assume that that's
2203  * not what we're dealing with.)
2204  */
2205  stats->stadistinct = track_cnt;
2206  }
2207  else
2208  {
2209  /*----------
2210  * Estimate the number of distinct values using the estimator
2211  * proposed by Haas and Stokes in IBM Research Report RJ 10025:
2212  * n*d / (n - f1 + f1*n/N)
2213  * where f1 is the number of distinct values that occurred
2214  * exactly once in our sample of n rows (from a total of N),
2215  * and d is the total number of distinct values in the sample.
2216  * This is their Duj1 estimator; the other estimators they
2217  * recommend are considerably more complex, and are numerically
2218  * very unstable when n is much smaller than N.
2219  *
2220  * In this calculation, we consider only non-nulls. We used to
2221  * include rows with null values in the n and N counts, but that
2222  * leads to inaccurate answers in columns with many nulls, and
2223  * it's intuitively bogus anyway considering the desired result is
2224  * the number of distinct non-null values.
2225  *
2226  * We assume (not very reliably!) that all the multiply-occurring
2227  * values are reflected in the final track[] list, and the other
2228  * nonnull values all appeared but once. (XXX this usually
2229  * results in a drastic overestimate of ndistinct. Can we do
2230  * any better?)
2231  *----------
2232  */
2233  int f1 = nonnull_cnt - summultiple;
2234  int d = f1 + nmultiple;
2235  double n = samplerows - null_cnt;
2236  double N = totalrows * (1.0 - stats->stanullfrac);
2237  double stadistinct;
2238 
2239  /* N == 0 shouldn't happen, but just in case ... */
2240  if (N > 0)
2241  stadistinct = (n * d) / ((n - f1) + f1 * n / N);
2242  else
2243  stadistinct = 0;
2244 
2245  /* Clamp to sane range in case of roundoff error */
2246  if (stadistinct < d)
2247  stadistinct = d;
2248  if (stadistinct > N)
2249  stadistinct = N;
2250  /* And round to integer */
2251  stats->stadistinct = floor(stadistinct + 0.5);
2252  }
2253 
2254  /*
2255  * If we estimated the number of distinct values at more than 10% of
2256  * the total row count (a very arbitrary limit), then assume that
2257  * stadistinct should scale with the row count rather than be a fixed
2258  * value.
2259  */
2260  if (stats->stadistinct > 0.1 * totalrows)
2261  stats->stadistinct = -(stats->stadistinct / totalrows);
2262 
2263  /*
2264  * Decide how many values are worth storing as most-common values. If
2265  * we are able to generate a complete MCV list (all the values in the
2266  * sample will fit, and we think these are all the ones in the table),
2267  * then do so. Otherwise, store only those values that are
2268  * significantly more common than the values not in the list.
2269  *
2270  * Note: the first of these cases is meant to address columns with
2271  * small, fixed sets of possible values, such as boolean or enum
2272  * columns. If we can *completely* represent the column population by
2273  * an MCV list that will fit into the stats target, then we should do
2274  * so and thus provide the planner with complete information. But if
2275  * the MCV list is not complete, it's generally worth being more
2276  * selective, and not just filling it all the way up to the stats
2277  * target.
2278  */
2279  if (track_cnt < track_max && toowide_cnt == 0 &&
2280  stats->stadistinct > 0 &&
2281  track_cnt <= num_mcv)
2282  {
2283  /* Track list includes all values seen, and all will fit */
2284  num_mcv = track_cnt;
2285  }
2286  else
2287  {
2288  int *mcv_counts;
2289 
2290  /* Incomplete list; decide how many values are worth keeping */
2291  if (num_mcv > track_cnt)
2292  num_mcv = track_cnt;
2293 
2294  if (num_mcv > 0)
2295  {
2296  mcv_counts = (int *) palloc(num_mcv * sizeof(int));
2297  for (i = 0; i < num_mcv; i++)
2298  mcv_counts[i] = track[i].count;
2299 
2300  num_mcv = analyze_mcv_list(mcv_counts, num_mcv,
2301  stats->stadistinct,
2302  stats->stanullfrac,
2303  samplerows, totalrows);
2304  }
2305  }
2306 
2307  /* Generate MCV slot entry */
2308  if (num_mcv > 0)
2309  {
2310  MemoryContext old_context;
2311  Datum *mcv_values;
2312  float4 *mcv_freqs;
2313 
2314  /* Must copy the target values into anl_context */
2315  old_context = MemoryContextSwitchTo(stats->anl_context);
2316  mcv_values = (Datum *) palloc(num_mcv * sizeof(Datum));
2317  mcv_freqs = (float4 *) palloc(num_mcv * sizeof(float4));
2318  for (i = 0; i < num_mcv; i++)
2319  {
2320  mcv_values[i] = datumCopy(track[i].value,
2321  stats->attrtype->typbyval,
2322  stats->attrtype->typlen);
2323  mcv_freqs[i] = (double) track[i].count / (double) samplerows;
2324  }
2325  MemoryContextSwitchTo(old_context);
2326 
2327  stats->stakind[0] = STATISTIC_KIND_MCV;
2328  stats->staop[0] = mystats->eqopr;
2329  stats->stacoll[0] = stats->attrcollid;
2330  stats->stanumbers[0] = mcv_freqs;
2331  stats->numnumbers[0] = num_mcv;
2332  stats->stavalues[0] = mcv_values;
2333  stats->numvalues[0] = num_mcv;
2334 
2335  /*
2336  * Accept the defaults for stats->statypid and others. They have
2337  * been set before we were called (see vacuum.h)
2338  */
2339  }
2340  }
2341  else if (null_cnt > 0)
2342  {
2343  /* We found only nulls; assume the column is entirely null */
2344  stats->stats_valid = true;
2345  stats->stanullfrac = 1.0;
2346  if (is_varwidth)
2347  stats->stawidth = 0; /* "unknown" */
2348  else
2349  stats->stawidth = stats->attrtype->typlen;
2350  stats->stadistinct = 0.0; /* "unknown" */
2351  }
2352 
2353  /* We don't need to bother cleaning up any of our temporary palloc's */
2354 }
Definition: fmgr.h:56
#define PointerGetDatum(X)
Definition: postgres.h:600
static int analyze_mcv_list(int *mcv_counts, int num_mcv, double stadistinct, double stanullfrac, int samplerows, double totalrows)
Definition: analyze.c:2948
Datum * stavalues[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:152
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Datum FunctionCall2Coll(FmgrInfo *flinfo, Oid collation, Datum arg1, Datum arg2)
Definition: fmgr.c:1148
Form_pg_attribute attr
Definition: vacuum.h:123
#define swapDatum(a, b)
Definition: analyze.c:1813
#define DatumGetCString(X)
Definition: postgres.h:610
int32 stawidth
Definition: vacuum.h:144
Oid stacoll[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:148
void fmgr_info(Oid functionId, FmgrInfo *finfo)
Definition: fmgr.c:126
int numnumbers[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:149
#define DatumGetBool(X)
Definition: postgres.h:437
Size toast_raw_datum_size(Datum value)
Definition: detoast.c:545
Datum datumCopy(Datum value, bool typByVal, int typLen)
Definition: datum.c:131
float4 stanullfrac
Definition: vacuum.h:143
Oid staop[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:147
bool stats_valid
Definition: vacuum.h:142
float float4
Definition: c.h:564
#define WIDTH_THRESHOLD
Definition: analyze.c:1810
uintptr_t Datum
Definition: postgres.h:411
int16 stakind[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:146
#define VARSIZE_ANY(PTR)
Definition: postgres.h:348
static struct @143 value
float4 * stanumbers[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:150
Oid attrcollid
Definition: vacuum.h:127
MemoryContext anl_context
Definition: vacuum.h:128
#define swapInt(a, b)
Definition: analyze.c:1812
#define DatumGetPointer(X)
Definition: postgres.h:593
int numvalues[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:151
Form_pg_type attrtype
Definition: vacuum.h:126
void * palloc(Size size)
Definition: mcxt.c:1062
int i
#define PG_DETOAST_DATUM(datum)
Definition: fmgr.h:240
int f1[ARRAY_SIZE]
Definition: sql-declare.c:113
void * extra_data
Definition: vacuum.h:136
void vacuum_delay_point(void)
Definition: vacuum.c:2149
float4 stadistinct
Definition: vacuum.h:145

◆ compute_index_stats()

static void compute_index_stats ( Relation  onerel,
double  totalrows,
AnlIndexData indexdata,
int  nindexes,
HeapTuple rows,
int  numrows,
MemoryContext  col_context 
)
static

Definition at line 832 of file analyze.c.

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, attnum, VacAttrStats::attr, AnlIndexData::attr_cnt, VacAttrStats::attrtype, VacAttrStats::compute_stats, CreateExecutorState(), datumCopy(), ExprContext::ecxt_scantuple, ExecDropSingleTupleTableSlot(), ExecPrepareQual(), ExecQual(), ExecStoreHeapTuple(), VacAttrStats::exprnulls, VacAttrStats::exprvals, FormIndexDatum(), FreeExecutorState(), GetPerTupleExprContext, i, IndexInfo::ii_Predicate, ind_fetch_func(), INDEX_MAX_KEYS, AnlIndexData::indexInfo, MakeSingleTupleTableSlot(), MemoryContextDelete(), MemoryContextResetAndDeleteChildren, MemoryContextSwitchTo(), NIL, palloc(), RelationGetDescr, ResetExprContext, VacAttrStats::rowstride, TTSOpsHeapTuple, AnlIndexData::tupleFract, AnlIndexData::vacattrstats, vacuum_delay_point(), and values.

Referenced by do_analyze_rel().

836 {
837  MemoryContext ind_context,
838  old_context;
840  bool isnull[INDEX_MAX_KEYS];
841  int ind,
842  i;
843 
844  ind_context = AllocSetContextCreate(anl_context,
845  "Analyze Index",
847  old_context = MemoryContextSwitchTo(ind_context);
848 
849  for (ind = 0; ind < nindexes; ind++)
850  {
851  AnlIndexData *thisdata = &indexdata[ind];
852  IndexInfo *indexInfo = thisdata->indexInfo;
853  int attr_cnt = thisdata->attr_cnt;
854  TupleTableSlot *slot;
855  EState *estate;
856  ExprContext *econtext;
857  ExprState *predicate;
858  Datum *exprvals;
859  bool *exprnulls;
860  int numindexrows,
861  tcnt,
862  rowno;
863  double totalindexrows;
864 
865  /* Ignore index if no columns to analyze and not partial */
866  if (attr_cnt == 0 && indexInfo->ii_Predicate == NIL)
867  continue;
868 
869  /*
870  * Need an EState for evaluation of index expressions and
871  * partial-index predicates. Create it in the per-index context to be
872  * sure it gets cleaned up at the bottom of the loop.
873  */
874  estate = CreateExecutorState();
875  econtext = GetPerTupleExprContext(estate);
876  /* Need a slot to hold the current heap tuple, too */
878  &TTSOpsHeapTuple);
879 
880  /* Arrange for econtext's scan tuple to be the tuple under test */
881  econtext->ecxt_scantuple = slot;
882 
883  /* Set up execution state for predicate. */
884  predicate = ExecPrepareQual(indexInfo->ii_Predicate, estate);
885 
886  /* Compute and save index expression values */
887  exprvals = (Datum *) palloc(numrows * attr_cnt * sizeof(Datum));
888  exprnulls = (bool *) palloc(numrows * attr_cnt * sizeof(bool));
889  numindexrows = 0;
890  tcnt = 0;
891  for (rowno = 0; rowno < numrows; rowno++)
892  {
893  HeapTuple heapTuple = rows[rowno];
894 
896 
897  /*
898  * Reset the per-tuple context each time, to reclaim any cruft
899  * left behind by evaluating the predicate or index expressions.
900  */
901  ResetExprContext(econtext);
902 
903  /* Set up for predicate or expression evaluation */
904  ExecStoreHeapTuple(heapTuple, slot, false);
905 
906  /* If index is partial, check predicate */
907  if (predicate != NULL)
908  {
909  if (!ExecQual(predicate, econtext))
910  continue;
911  }
912  numindexrows++;
913 
914  if (attr_cnt > 0)
915  {
916  /*
917  * Evaluate the index row to compute expression values. We
918  * could do this by hand, but FormIndexDatum is convenient.
919  */
920  FormIndexDatum(indexInfo,
921  slot,
922  estate,
923  values,
924  isnull);
925 
926  /*
927  * Save just the columns we care about. We copy the values
928  * into ind_context from the estate's per-tuple context.
929  */
930  for (i = 0; i < attr_cnt; i++)
931  {
932  VacAttrStats *stats = thisdata->vacattrstats[i];
933  int attnum = stats->attr->attnum;
934 
935  if (isnull[attnum - 1])
936  {
937  exprvals[tcnt] = (Datum) 0;
938  exprnulls[tcnt] = true;
939  }
940  else
941  {
942  exprvals[tcnt] = datumCopy(values[attnum - 1],
943  stats->attrtype->typbyval,
944  stats->attrtype->typlen);
945  exprnulls[tcnt] = false;
946  }
947  tcnt++;
948  }
949  }
950  }
951 
952  /*
953  * Having counted the number of rows that pass the predicate in the
954  * sample, we can estimate the total number of rows in the index.
955  */
956  thisdata->tupleFract = (double) numindexrows / (double) numrows;
957  totalindexrows = ceil(thisdata->tupleFract * totalrows);
958 
959  /*
960  * Now we can compute the statistics for the expression columns.
961  */
962  if (numindexrows > 0)
963  {
964  MemoryContextSwitchTo(col_context);
965  for (i = 0; i < attr_cnt; i++)
966  {
967  VacAttrStats *stats = thisdata->vacattrstats[i];
968 
969  stats->exprvals = exprvals + i;
970  stats->exprnulls = exprnulls + i;
971  stats->rowstride = attr_cnt;
972  stats->compute_stats(stats,
974  numindexrows,
975  totalindexrows);
976 
978  }
979  }
980 
981  /* And clean up */
982  MemoryContextSwitchTo(ind_context);
983 
985  FreeExecutorState(estate);
987  }
988 
989  MemoryContextSwitchTo(old_context);
990  MemoryContextDelete(ind_context);
991 }
int rowstride
Definition: vacuum.h:174
void FormIndexDatum(IndexInfo *indexInfo, TupleTableSlot *slot, EState *estate, Datum *values, bool *isnull)
Definition: index.c:2662
#define NIL
Definition: pg_list.h:65
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:218
#define AllocSetContextCreate
Definition: memutils.h:173
List * ii_Predicate
Definition: execnodes.h:164
#define RelationGetDescr(relation)
Definition: rel.h:503
TupleTableSlot * MakeSingleTupleTableSlot(TupleDesc tupdesc, const TupleTableSlotOps *tts_ops)
Definition: execTuples.c:1238
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
static bool ExecQual(ExprState *state, ExprContext *econtext)
Definition: executor.h:396
Form_pg_attribute attr
Definition: vacuum.h:123
int attr_cnt
Definition: analyze.c:77
void FreeExecutorState(EState *estate)
Definition: execUtils.c:186
#define GetPerTupleExprContext(estate)
Definition: executor.h:533
bool * exprnulls
Definition: vacuum.h:173
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:195
static MemoryContext anl_context
Definition: analyze.c:85
void ExecDropSingleTupleTableSlot(TupleTableSlot *slot)
Definition: execTuples.c:1254
ExprState * ExecPrepareQual(List *qual, EState *estate)
Definition: execExpr.c:774
Datum datumCopy(Datum value, bool typByVal, int typLen)
Definition: datum.c:131
EState * CreateExecutorState(void)
Definition: execUtils.c:90
Datum * exprvals
Definition: vacuum.h:172
#define MemoryContextResetAndDeleteChildren(ctx)
Definition: memutils.h:67
uintptr_t Datum
Definition: postgres.h:411
static Datum ind_fetch_func(VacAttrStatsP stats, int rownum, bool *isNull)
Definition: analyze.c:1780
int16 attnum
Definition: pg_attribute.h:83
#define INDEX_MAX_KEYS
TupleTableSlot * ecxt_scantuple
Definition: execnodes.h:227
double tupleFract
Definition: analyze.c:75
static Datum values[MAXATTR]
Definition: bootstrap.c:156
Form_pg_type attrtype
Definition: vacuum.h:126
void * palloc(Size size)
Definition: mcxt.c:1062
VacAttrStats ** vacattrstats
Definition: analyze.c:76
int i
const TupleTableSlotOps TTSOpsHeapTuple
Definition: execTuples.c:84
AnalyzeAttrComputeStatsFunc compute_stats
Definition: vacuum.h:134
void vacuum_delay_point(void)
Definition: vacuum.c:2149
TupleTableSlot * ExecStoreHeapTuple(HeapTuple tuple, TupleTableSlot *slot, bool shouldFree)
Definition: execTuples.c:1352
#define ResetExprContext(econtext)
Definition: executor.h:527
IndexInfo * indexInfo
Definition: analyze.c:74

◆ compute_scalar_stats()

static void compute_scalar_stats ( VacAttrStatsP  stats,
AnalyzeAttrFetchFunc  fetchfunc,
int  samplerows,
double  totalrows 
)
static

Definition at line 2370 of file analyze.c.

References SortSupportData::abbreviate, analyze_mcv_list(), VacAttrStats::anl_context, Assert, VacAttrStats::attr, VacAttrStats::attrcollid, VacAttrStats::attrtype, compare_mcvs(), compare_scalars(), ScalarMCVItem::count, CurrentMemoryContext, datumCopy(), DatumGetCString, DatumGetPointer, generate_unaccent_rules::dest, StdAnalyzeData::eqopr, VacAttrStats::extra_data, f1, ScalarMCVItem::first, i, StdAnalyzeData::ltopr, MemoryContextSwitchTo(), VacAttrStats::numnumbers, VacAttrStats::numvalues, palloc(), PG_DETOAST_DATUM, PointerGetDatum, PrepareSortSupportFromOrderingOp(), qsort, qsort_arg(), CompareScalarsContext::ssup, SortSupportData::ssup_collation, SortSupportData::ssup_cxt, SortSupportData::ssup_nulls_first, VacAttrStats::stacoll, VacAttrStats::stadistinct, VacAttrStats::stakind, VacAttrStats::stanullfrac, VacAttrStats::stanumbers, VacAttrStats::staop, VacAttrStats::stats_valid, VacAttrStats::stavalues, VacAttrStats::stawidth, toast_raw_datum_size(), ScalarItem::tupno, CompareScalarsContext::tupnoLink, vacuum_delay_point(), ScalarItem::value, value, values, VARSIZE_ANY, and WIDTH_THRESHOLD.

Referenced by std_typanalyze().

2374 {
2375  int i;
2376  int null_cnt = 0;
2377  int nonnull_cnt = 0;
2378  int toowide_cnt = 0;
2379  double total_width = 0;
2380  bool is_varlena = (!stats->attrtype->typbyval &&
2381  stats->attrtype->typlen == -1);
2382  bool is_varwidth = (!stats->attrtype->typbyval &&
2383  stats->attrtype->typlen < 0);
2384  double corr_xysum;
2385  SortSupportData ssup;
2386  ScalarItem *values;
2387  int values_cnt = 0;
2388  int *tupnoLink;
2389  ScalarMCVItem *track;
2390  int track_cnt = 0;
2391  int num_mcv = stats->attr->attstattarget;
2392  int num_bins = stats->attr->attstattarget;
2393  StdAnalyzeData *mystats = (StdAnalyzeData *) stats->extra_data;
2394 
2395  values = (ScalarItem *) palloc(samplerows * sizeof(ScalarItem));
2396  tupnoLink = (int *) palloc(samplerows * sizeof(int));
2397  track = (ScalarMCVItem *) palloc(num_mcv * sizeof(ScalarMCVItem));
2398 
2399  memset(&ssup, 0, sizeof(ssup));
2401  ssup.ssup_collation = stats->attrcollid;
2402  ssup.ssup_nulls_first = false;
2403 
2404  /*
2405  * For now, don't perform abbreviated key conversion, because full values
2406  * are required for MCV slot generation. Supporting that optimization
2407  * would necessitate teaching compare_scalars() to call a tie-breaker.
2408  */
2409  ssup.abbreviate = false;
2410 
2411  PrepareSortSupportFromOrderingOp(mystats->ltopr, &ssup);
2412 
2413  /* Initial scan to find sortable values */
2414  for (i = 0; i < samplerows; i++)
2415  {
2416  Datum value;
2417  bool isnull;
2418 
2420 
2421  value = fetchfunc(stats, i, &isnull);
2422 
2423  /* Check for null/nonnull */
2424  if (isnull)
2425  {
2426  null_cnt++;
2427  continue;
2428  }
2429  nonnull_cnt++;
2430 
2431  /*
2432  * If it's a variable-width field, add up widths for average width
2433  * calculation. Note that if the value is toasted, we use the toasted
2434  * width. We don't bother with this calculation if it's a fixed-width
2435  * type.
2436  */
2437  if (is_varlena)
2438  {
2439  total_width += VARSIZE_ANY(DatumGetPointer(value));
2440 
2441  /*
2442  * If the value is toasted, we want to detoast it just once to
2443  * avoid repeated detoastings and resultant excess memory usage
2444  * during the comparisons. Also, check to see if the value is
2445  * excessively wide, and if so don't detoast at all --- just
2446  * ignore the value.
2447  */
2449  {
2450  toowide_cnt++;
2451  continue;
2452  }
2453  value = PointerGetDatum(PG_DETOAST_DATUM(value));
2454  }
2455  else if (is_varwidth)
2456  {
2457  /* must be cstring */
2458  total_width += strlen(DatumGetCString(value)) + 1;
2459  }
2460 
2461  /* Add it to the list to be sorted */
2462  values[values_cnt].value = value;
2463  values[values_cnt].tupno = values_cnt;
2464  tupnoLink[values_cnt] = values_cnt;
2465  values_cnt++;
2466  }
2467 
2468  /* We can only compute real stats if we found some sortable values. */
2469  if (values_cnt > 0)
2470  {
2471  int ndistinct, /* # distinct values in sample */
2472  nmultiple, /* # that appear multiple times */
2473  num_hist,
2474  dups_cnt;
2475  int slot_idx = 0;
2477 
2478  /* Sort the collected values */
2479  cxt.ssup = &ssup;
2480  cxt.tupnoLink = tupnoLink;
2481  qsort_arg((void *) values, values_cnt, sizeof(ScalarItem),
2482  compare_scalars, (void *) &cxt);
2483 
2484  /*
2485  * Now scan the values in order, find the most common ones, and also
2486  * accumulate ordering-correlation statistics.
2487  *
2488  * To determine which are most common, we first have to count the
2489  * number of duplicates of each value. The duplicates are adjacent in
2490  * the sorted list, so a brute-force approach is to compare successive
2491  * datum values until we find two that are not equal. However, that
2492  * requires N-1 invocations of the datum comparison routine, which are
2493  * completely redundant with work that was done during the sort. (The
2494  * sort algorithm must at some point have compared each pair of items
2495  * that are adjacent in the sorted order; otherwise it could not know
2496  * that it's ordered the pair correctly.) We exploit this by having
2497  * compare_scalars remember the highest tupno index that each
2498  * ScalarItem has been found equal to. At the end of the sort, a
2499  * ScalarItem's tupnoLink will still point to itself if and only if it
2500  * is the last item of its group of duplicates (since the group will
2501  * be ordered by tupno).
2502  */
2503  corr_xysum = 0;
2504  ndistinct = 0;
2505  nmultiple = 0;
2506  dups_cnt = 0;
2507  for (i = 0; i < values_cnt; i++)
2508  {
2509  int tupno = values[i].tupno;
2510 
2511  corr_xysum += ((double) i) * ((double) tupno);
2512  dups_cnt++;
2513  if (tupnoLink[tupno] == tupno)
2514  {
2515  /* Reached end of duplicates of this value */
2516  ndistinct++;
2517  if (dups_cnt > 1)
2518  {
2519  nmultiple++;
2520  if (track_cnt < num_mcv ||
2521  dups_cnt > track[track_cnt - 1].count)
2522  {
2523  /*
2524  * Found a new item for the mcv list; find its
2525  * position, bubbling down old items if needed. Loop
2526  * invariant is that j points at an empty/ replaceable
2527  * slot.
2528  */
2529  int j;
2530 
2531  if (track_cnt < num_mcv)
2532  track_cnt++;
2533  for (j = track_cnt - 1; j > 0; j--)
2534  {
2535  if (dups_cnt <= track[j - 1].count)
2536  break;
2537  track[j].count = track[j - 1].count;
2538  track[j].first = track[j - 1].first;
2539  }
2540  track[j].count = dups_cnt;
2541  track[j].first = i + 1 - dups_cnt;
2542  }
2543  }
2544  dups_cnt = 0;
2545  }
2546  }
2547 
2548  stats->stats_valid = true;
2549  /* Do the simple null-frac and width stats */
2550  stats->stanullfrac = (double) null_cnt / (double) samplerows;
2551  if (is_varwidth)
2552  stats->stawidth = total_width / (double) nonnull_cnt;
2553  else
2554  stats->stawidth = stats->attrtype->typlen;
2555 
2556  if (nmultiple == 0)
2557  {
2558  /*
2559  * If we found no repeated non-null values, assume it's a unique
2560  * column; but be sure to discount for any nulls we found.
2561  */
2562  stats->stadistinct = -1.0 * (1.0 - stats->stanullfrac);
2563  }
2564  else if (toowide_cnt == 0 && nmultiple == ndistinct)
2565  {
2566  /*
2567  * Every value in the sample appeared more than once. Assume the
2568  * column has just these values. (This case is meant to address
2569  * columns with small, fixed sets of possible values, such as
2570  * boolean or enum columns. If there are any values that appear
2571  * just once in the sample, including too-wide values, we should
2572  * assume that that's not what we're dealing with.)
2573  */
2574  stats->stadistinct = ndistinct;
2575  }
2576  else
2577  {
2578  /*----------
2579  * Estimate the number of distinct values using the estimator
2580  * proposed by Haas and Stokes in IBM Research Report RJ 10025:
2581  * n*d / (n - f1 + f1*n/N)
2582  * where f1 is the number of distinct values that occurred
2583  * exactly once in our sample of n rows (from a total of N),
2584  * and d is the total number of distinct values in the sample.
2585  * This is their Duj1 estimator; the other estimators they
2586  * recommend are considerably more complex, and are numerically
2587  * very unstable when n is much smaller than N.
2588  *
2589  * In this calculation, we consider only non-nulls. We used to
2590  * include rows with null values in the n and N counts, but that
2591  * leads to inaccurate answers in columns with many nulls, and
2592  * it's intuitively bogus anyway considering the desired result is
2593  * the number of distinct non-null values.
2594  *
2595  * Overwidth values are assumed to have been distinct.
2596  *----------
2597  */
2598  int f1 = ndistinct - nmultiple + toowide_cnt;
2599  int d = f1 + nmultiple;
2600  double n = samplerows - null_cnt;
2601  double N = totalrows * (1.0 - stats->stanullfrac);
2602  double stadistinct;
2603 
2604  /* N == 0 shouldn't happen, but just in case ... */
2605  if (N > 0)
2606  stadistinct = (n * d) / ((n - f1) + f1 * n / N);
2607  else
2608  stadistinct = 0;
2609 
2610  /* Clamp to sane range in case of roundoff error */
2611  if (stadistinct < d)
2612  stadistinct = d;
2613  if (stadistinct > N)
2614  stadistinct = N;
2615  /* And round to integer */
2616  stats->stadistinct = floor(stadistinct + 0.5);
2617  }
2618 
2619  /*
2620  * If we estimated the number of distinct values at more than 10% of
2621  * the total row count (a very arbitrary limit), then assume that
2622  * stadistinct should scale with the row count rather than be a fixed
2623  * value.
2624  */
2625  if (stats->stadistinct > 0.1 * totalrows)
2626  stats->stadistinct = -(stats->stadistinct / totalrows);
2627 
2628  /*
2629  * Decide how many values are worth storing as most-common values. If
2630  * we are able to generate a complete MCV list (all the values in the
2631  * sample will fit, and we think these are all the ones in the table),
2632  * then do so. Otherwise, store only those values that are
2633  * significantly more common than the values not in the list.
2634  *
2635  * Note: the first of these cases is meant to address columns with
2636  * small, fixed sets of possible values, such as boolean or enum
2637  * columns. If we can *completely* represent the column population by
2638  * an MCV list that will fit into the stats target, then we should do
2639  * so and thus provide the planner with complete information. But if
2640  * the MCV list is not complete, it's generally worth being more
2641  * selective, and not just filling it all the way up to the stats
2642  * target.
2643  */
2644  if (track_cnt == ndistinct && toowide_cnt == 0 &&
2645  stats->stadistinct > 0 &&
2646  track_cnt <= num_mcv)
2647  {
2648  /* Track list includes all values seen, and all will fit */
2649  num_mcv = track_cnt;
2650  }
2651  else
2652  {
2653  int *mcv_counts;
2654 
2655  /* Incomplete list; decide how many values are worth keeping */
2656  if (num_mcv > track_cnt)
2657  num_mcv = track_cnt;
2658 
2659  if (num_mcv > 0)
2660  {
2661  mcv_counts = (int *) palloc(num_mcv * sizeof(int));
2662  for (i = 0; i < num_mcv; i++)
2663  mcv_counts[i] = track[i].count;
2664 
2665  num_mcv = analyze_mcv_list(mcv_counts, num_mcv,
2666  stats->stadistinct,
2667  stats->stanullfrac,
2668  samplerows, totalrows);
2669  }
2670  }
2671 
2672  /* Generate MCV slot entry */
2673  if (num_mcv > 0)
2674  {
2675  MemoryContext old_context;
2676  Datum *mcv_values;
2677  float4 *mcv_freqs;
2678 
2679  /* Must copy the target values into anl_context */
2680  old_context = MemoryContextSwitchTo(stats->anl_context);
2681  mcv_values = (Datum *) palloc(num_mcv * sizeof(Datum));
2682  mcv_freqs = (float4 *) palloc(num_mcv * sizeof(float4));
2683  for (i = 0; i < num_mcv; i++)
2684  {
2685  mcv_values[i] = datumCopy(values[track[i].first].value,
2686  stats->attrtype->typbyval,
2687  stats->attrtype->typlen);
2688  mcv_freqs[i] = (double) track[i].count / (double) samplerows;
2689  }
2690  MemoryContextSwitchTo(old_context);
2691 
2692  stats->stakind[slot_idx] = STATISTIC_KIND_MCV;
2693  stats->staop[slot_idx] = mystats->eqopr;
2694  stats->stacoll[slot_idx] = stats->attrcollid;
2695  stats->stanumbers[slot_idx] = mcv_freqs;
2696  stats->numnumbers[slot_idx] = num_mcv;
2697  stats->stavalues[slot_idx] = mcv_values;
2698  stats->numvalues[slot_idx] = num_mcv;
2699 
2700  /*
2701  * Accept the defaults for stats->statypid and others. They have
2702  * been set before we were called (see vacuum.h)
2703  */
2704  slot_idx++;
2705  }
2706 
2707  /*
2708  * Generate a histogram slot entry if there are at least two distinct
2709  * values not accounted for in the MCV list. (This ensures the
2710  * histogram won't collapse to empty or a singleton.)
2711  */
2712  num_hist = ndistinct - num_mcv;
2713  if (num_hist > num_bins)
2714  num_hist = num_bins + 1;
2715  if (num_hist >= 2)
2716  {
2717  MemoryContext old_context;
2718  Datum *hist_values;
2719  int nvals;
2720  int pos,
2721  posfrac,
2722  delta,
2723  deltafrac;
2724 
2725  /* Sort the MCV items into position order to speed next loop */
2726  qsort((void *) track, num_mcv,
2727  sizeof(ScalarMCVItem), compare_mcvs);
2728 
2729  /*
2730  * Collapse out the MCV items from the values[] array.
2731  *
2732  * Note we destroy the values[] array here... but we don't need it
2733  * for anything more. We do, however, still need values_cnt.
2734  * nvals will be the number of remaining entries in values[].
2735  */
2736  if (num_mcv > 0)
2737  {
2738  int src,
2739  dest;
2740  int j;
2741 
2742  src = dest = 0;
2743  j = 0; /* index of next interesting MCV item */
2744  while (src < values_cnt)
2745  {
2746  int ncopy;
2747 
2748  if (j < num_mcv)
2749  {
2750  int first = track[j].first;
2751 
2752  if (src >= first)
2753  {
2754  /* advance past this MCV item */
2755  src = first + track[j].count;
2756  j++;
2757  continue;
2758  }
2759  ncopy = first - src;
2760  }
2761  else
2762  ncopy = values_cnt - src;
2763  memmove(&values[dest], &values[src],
2764  ncopy * sizeof(ScalarItem));
2765  src += ncopy;
2766  dest += ncopy;
2767  }
2768  nvals = dest;
2769  }
2770  else
2771  nvals = values_cnt;
2772  Assert(nvals >= num_hist);
2773 
2774  /* Must copy the target values into anl_context */
2775  old_context = MemoryContextSwitchTo(stats->anl_context);
2776  hist_values = (Datum *) palloc(num_hist * sizeof(Datum));
2777 
2778  /*
2779  * The object of this loop is to copy the first and last values[]
2780  * entries along with evenly-spaced values in between. So the
2781  * i'th value is values[(i * (nvals - 1)) / (num_hist - 1)]. But
2782  * computing that subscript directly risks integer overflow when
2783  * the stats target is more than a couple thousand. Instead we
2784  * add (nvals - 1) / (num_hist - 1) to pos at each step, tracking
2785  * the integral and fractional parts of the sum separately.
2786  */
2787  delta = (nvals - 1) / (num_hist - 1);
2788  deltafrac = (nvals - 1) % (num_hist - 1);
2789  pos = posfrac = 0;
2790 
2791  for (i = 0; i < num_hist; i++)
2792  {
2793  hist_values[i] = datumCopy(values[pos].value,
2794  stats->attrtype->typbyval,
2795  stats->attrtype->typlen);
2796  pos += delta;
2797  posfrac += deltafrac;
2798  if (posfrac >= (num_hist - 1))
2799  {
2800  /* fractional part exceeds 1, carry to integer part */
2801  pos++;
2802  posfrac -= (num_hist - 1);
2803  }
2804  }
2805 
2806  MemoryContextSwitchTo(old_context);
2807 
2808  stats->stakind[slot_idx] = STATISTIC_KIND_HISTOGRAM;
2809  stats->staop[slot_idx] = mystats->ltopr;
2810  stats->stacoll[slot_idx] = stats->attrcollid;
2811  stats->stavalues[slot_idx] = hist_values;
2812  stats->numvalues[slot_idx] = num_hist;
2813 
2814  /*
2815  * Accept the defaults for stats->statypid and others. They have
2816  * been set before we were called (see vacuum.h)
2817  */
2818  slot_idx++;
2819  }
2820 
2821  /* Generate a correlation entry if there are multiple values */
2822  if (values_cnt > 1)
2823  {
2824  MemoryContext old_context;
2825  float4 *corrs;
2826  double corr_xsum,
2827  corr_x2sum;
2828 
2829  /* Must copy the target values into anl_context */
2830  old_context = MemoryContextSwitchTo(stats->anl_context);
2831  corrs = (float4 *) palloc(sizeof(float4));
2832  MemoryContextSwitchTo(old_context);
2833 
2834  /*----------
2835  * Since we know the x and y value sets are both
2836  * 0, 1, ..., values_cnt-1
2837  * we have sum(x) = sum(y) =
2838  * (values_cnt-1)*values_cnt / 2
2839  * and sum(x^2) = sum(y^2) =
2840  * (values_cnt-1)*values_cnt*(2*values_cnt-1) / 6.
2841  *----------
2842  */
2843  corr_xsum = ((double) (values_cnt - 1)) *
2844  ((double) values_cnt) / 2.0;
2845  corr_x2sum = ((double) (values_cnt - 1)) *
2846  ((double) values_cnt) * (double) (2 * values_cnt - 1) / 6.0;
2847 
2848  /* And the correlation coefficient reduces to */
2849  corrs[0] = (values_cnt * corr_xysum - corr_xsum * corr_xsum) /
2850  (values_cnt * corr_x2sum - corr_xsum * corr_xsum);
2851 
2852  stats->stakind[slot_idx] = STATISTIC_KIND_CORRELATION;
2853  stats->staop[slot_idx] = mystats->ltopr;
2854  stats->stacoll[slot_idx] = stats->attrcollid;
2855  stats->stanumbers[slot_idx] = corrs;
2856  stats->numnumbers[slot_idx] = 1;
2857  slot_idx++;
2858  }
2859  }
2860  else if (nonnull_cnt > 0)
2861  {
2862  /* We found some non-null values, but they were all too wide */
2863  Assert(nonnull_cnt == toowide_cnt);
2864  stats->stats_valid = true;
2865  /* Do the simple null-frac and width stats */
2866  stats->stanullfrac = (double) null_cnt / (double) samplerows;
2867  if (is_varwidth)
2868  stats->stawidth = total_width / (double) nonnull_cnt;
2869  else
2870  stats->stawidth = stats->attrtype->typlen;
2871  /* Assume all too-wide values are distinct, so it's a unique column */
2872  stats->stadistinct = -1.0 * (1.0 - stats->stanullfrac);
2873  }
2874  else if (null_cnt > 0)
2875  {
2876  /* We found only nulls; assume the column is entirely null */
2877  stats->stats_valid = true;
2878  stats->stanullfrac = 1.0;
2879  if (is_varwidth)
2880  stats->stawidth = 0; /* "unknown" */
2881  else
2882  stats->stawidth = stats->attrtype->typlen;
2883  stats->stadistinct = 0.0; /* "unknown" */
2884  }
2885 
2886  /* We don't need to bother cleaning up any of our temporary palloc's */
2887 }
bool ssup_nulls_first
Definition: sortsupport.h:75
static int compare_mcvs(const void *a, const void *b)
Definition: analyze.c:2930
#define PointerGetDatum(X)
Definition: postgres.h:600
static int compare_scalars(const void *a, const void *b, void *arg)
Definition: analyze.c:2899
static int analyze_mcv_list(int *mcv_counts, int num_mcv, double stadistinct, double stanullfrac, int samplerows, double totalrows)
Definition: analyze.c:2948
void PrepareSortSupportFromOrderingOp(Oid orderingOp, SortSupport ssup)
Definition: sortsupport.c:135
Datum * stavalues[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:152
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Form_pg_attribute attr
Definition: vacuum.h:123
#define DatumGetCString(X)
Definition: postgres.h:610
int32 stawidth
Definition: vacuum.h:144
Oid stacoll[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:148
MemoryContext ssup_cxt
Definition: sortsupport.h:66
SortSupport ssup
Definition: analyze.c:1826
int numnumbers[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:149
MemoryContext CurrentMemoryContext
Definition: mcxt.c:42
Size toast_raw_datum_size(Datum value)
Definition: detoast.c:545
Datum datumCopy(Datum value, bool typByVal, int typLen)
Definition: datum.c:131
float4 stanullfrac
Definition: vacuum.h:143
void qsort_arg(void *base, size_t nel, size_t elsize, qsort_arg_comparator cmp, void *arg)
Oid staop[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:147
bool stats_valid
Definition: vacuum.h:142
float float4
Definition: c.h:564
#define WIDTH_THRESHOLD
Definition: analyze.c:1810
uintptr_t Datum
Definition: postgres.h:411
int16 stakind[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:146
#define VARSIZE_ANY(PTR)
Definition: postgres.h:348
static struct @143 value
#define Assert(condition)
Definition: c.h:804
float4 * stanumbers[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:150
Oid attrcollid
Definition: vacuum.h:127
MemoryContext anl_context
Definition: vacuum.h:128
#define DatumGetPointer(X)
Definition: postgres.h:593
static Datum values[MAXATTR]
Definition: bootstrap.c:156
int numvalues[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:151
Form_pg_type attrtype
Definition: vacuum.h:126
void * palloc(Size size)
Definition: mcxt.c:1062
int i
#define PG_DETOAST_DATUM(datum)
Definition: fmgr.h:240
int f1[ARRAY_SIZE]
Definition: sql-declare.c:113
void * extra_data
Definition: vacuum.h:136
#define qsort(a, b, c, d)
Definition: port.h:505
void vacuum_delay_point(void)
Definition: vacuum.c:2149
float4 stadistinct
Definition: vacuum.h:145

◆ compute_trivial_stats()

static void compute_trivial_stats ( VacAttrStatsP  stats,
AnalyzeAttrFetchFunc  fetchfunc,
int  samplerows,
double  totalrows 
)
static

Definition at line 1937 of file analyze.c.

References VacAttrStats::attrtype, DatumGetCString, DatumGetPointer, i, VacAttrStats::stadistinct, VacAttrStats::stanullfrac, VacAttrStats::stats_valid, VacAttrStats::stawidth, vacuum_delay_point(), value, and VARSIZE_ANY.

Referenced by std_typanalyze().

1941 {
1942  int i;
1943  int null_cnt = 0;
1944  int nonnull_cnt = 0;
1945  double total_width = 0;
1946  bool is_varlena = (!stats->attrtype->typbyval &&
1947  stats->attrtype->typlen == -1);
1948  bool is_varwidth = (!stats->attrtype->typbyval &&
1949  stats->attrtype->typlen < 0);
1950 
1951  for (i = 0; i < samplerows; i++)
1952  {
1953  Datum value;
1954  bool isnull;
1955 
1957 
1958  value = fetchfunc(stats, i, &isnull);
1959 
1960  /* Check for null/nonnull */
1961  if (isnull)
1962  {
1963  null_cnt++;
1964  continue;
1965  }
1966  nonnull_cnt++;
1967 
1968  /*
1969  * If it's a variable-width field, add up widths for average width
1970  * calculation. Note that if the value is toasted, we use the toasted
1971  * width. We don't bother with this calculation if it's a fixed-width
1972  * type.
1973  */
1974  if (is_varlena)
1975  {
1976  total_width += VARSIZE_ANY(DatumGetPointer(value));
1977  }
1978  else if (is_varwidth)
1979  {
1980  /* must be cstring */
1981  total_width += strlen(DatumGetCString(value)) + 1;
1982  }
1983  }
1984 
1985  /* We can only compute average width if we found some non-null values. */
1986  if (nonnull_cnt > 0)
1987  {
1988  stats->stats_valid = true;
1989  /* Do the simple null-frac and width stats */
1990  stats->stanullfrac = (double) null_cnt / (double) samplerows;
1991  if (is_varwidth)
1992  stats->stawidth = total_width / (double) nonnull_cnt;
1993  else
1994  stats->stawidth = stats->attrtype->typlen;
1995  stats->stadistinct = 0.0; /* "unknown" */
1996  }
1997  else if (null_cnt > 0)
1998  {
1999  /* We found only nulls; assume the column is entirely null */
2000  stats->stats_valid = true;
2001  stats->stanullfrac = 1.0;
2002  if (is_varwidth)
2003  stats->stawidth = 0; /* "unknown" */
2004  else
2005  stats->stawidth = stats->attrtype->typlen;
2006  stats->stadistinct = 0.0; /* "unknown" */
2007  }
2008 }
#define DatumGetCString(X)
Definition: postgres.h:610
int32 stawidth
Definition: vacuum.h:144
float4 stanullfrac
Definition: vacuum.h:143
bool stats_valid
Definition: vacuum.h:142
uintptr_t Datum
Definition: postgres.h:411
#define VARSIZE_ANY(PTR)
Definition: postgres.h:348
static struct @143 value
#define DatumGetPointer(X)
Definition: postgres.h:593
Form_pg_type attrtype
Definition: vacuum.h:126
int i
void vacuum_delay_point(void)
Definition: vacuum.c:2149
float4 stadistinct
Definition: vacuum.h:145

◆ do_analyze_rel()

static void do_analyze_rel ( Relation  onerel,
VacuumParams params,
List va_cols,
AcquireSampleRowsFunc  acquirefunc,
BlockNumber  relpages,
bool  inh,
bool  in_outer_xact,
int  elevel 
)
static

Definition at line 290 of file analyze.c.

References _, AccessShareLock, acquire_inherited_sample_rows(), ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, IndexVacuumInfo::analyze_only, appendStringInfo(), AtEOXact_GUC(), attnameAttNum(), VacAttrStats::attr, AnlIndexData::attr_cnt, bms_add_member(), bms_is_member(), buf, BuildIndexInfo(), BuildRelationExtStatistics(), compute_index_stats(), VacAttrStats::compute_stats, ComputeExtStatisticsRows(), CurrentMemoryContext, StringInfoData::data, elevel, elog, ereport, errcode(), errmsg(), errmsg_internal(), ERROR, IndexVacuumInfo::estimated_count, examine_attribute(), get_attribute_options(), get_database_name(), get_namespace_name(), GetCurrentTimestamp(), GetUserIdAndSecContext(), i, IndexInfo::ii_Expressions, IndexInfo::ii_IndexAttrNumbers, IndexInfo::ii_NumIndexAttrs, IndexVacuumInfo::index, index_vacuum_cleanup(), AnlIndexData::indexInfo, initStringInfo(), InvalidAttrNumber, InvalidMultiXactId, InvalidTransactionId, IsAutoVacuumWorkerProcess(), lfirst, list_free(), list_head(), list_length(), lnext(), LOG, VacuumParams::log_min_duration, MemoryContextDelete(), MemoryContextResetAndDeleteChildren, MemoryContextSwitchTo(), IndexVacuumInfo::message_level, VacAttrStats::minrows, MyDatabaseId, AttributeOpts::n_distinct, AttributeOpts::n_distinct_inherited, TupleDescData::natts, NewGUCNestLevel(), NIL, NoLock, IndexVacuumInfo::num_heap_tuples, VacuumParams::options, palloc(), palloc0(), pfree(), pg_rusage_init(), pg_rusage_show(), pgstat_progress_update_param(), pgstat_report_analyze(), pgStatBlockReadTime, pgStatBlockWriteTime, PROGRESS_ANALYZE_PHASE, PROGRESS_ANALYZE_PHASE_ACQUIRE_SAMPLE_ROWS, PROGRESS_ANALYZE_PHASE_ACQUIRE_SAMPLE_ROWS_INH, PROGRESS_ANALYZE_PHASE_COMPUTE_STATS, PROGRESS_ANALYZE_PHASE_FINALIZE_ANALYZE, RelationData::rd_att, RelationData::rd_rel, RelationGetIndexList(), RelationGetNamespace, RelationGetNumberOfBlocks, RelationGetRelationName, RelationGetRelid, VacAttrStats::rows, SECURITY_RESTRICTED_OPERATION, SetUserIdAndSecContext(), VacAttrStats::stadistinct, std_fetch_func(), IndexVacuumInfo::strategy, strVal, TimestampDifferenceExceeds(), TimestampDifferenceMilliseconds(), track_io_timing, VacAttrStats::tupDesc, AnlIndexData::tupleFract, update_attstats(), vac_close_indexes(), vac_open_indexes(), vac_strategy, vac_update_relstats(), AnlIndexData::vacattrstats, VACOPT_VACUUM, VacuumPageDirty, VacuumPageHit, VacuumPageMiss, and visibilitymap_count().

Referenced by analyze_rel().

294 {
295  int attr_cnt,
296  tcnt,
297  i,
298  ind;
299  Relation *Irel;
300  int nindexes;
301  bool hasindex;
302  VacAttrStats **vacattrstats;
303  AnlIndexData *indexdata;
304  int targrows,
305  numrows,
306  minrows;
307  double totalrows,
308  totaldeadrows;
309  HeapTuple *rows;
310  PGRUsage ru0;
311  TimestampTz starttime = 0;
312  MemoryContext caller_context;
313  Oid save_userid;
314  int save_sec_context;
315  int save_nestlevel;
316  int64 AnalyzePageHit = VacuumPageHit;
317  int64 AnalyzePageMiss = VacuumPageMiss;
318  int64 AnalyzePageDirty = VacuumPageDirty;
319  PgStat_Counter startreadtime = 0;
320  PgStat_Counter startwritetime = 0;
321 
322  if (inh)
323  ereport(elevel,
324  (errmsg("analyzing \"%s.%s\" inheritance tree",
326  RelationGetRelationName(onerel))));
327  else
328  ereport(elevel,
329  (errmsg("analyzing \"%s.%s\"",
331  RelationGetRelationName(onerel))));
332 
333  /*
334  * Set up a working context so that we can easily free whatever junk gets
335  * created.
336  */
338  "Analyze",
340  caller_context = MemoryContextSwitchTo(anl_context);
341 
342  /*
343  * Switch to the table owner's userid, so that any index functions are run
344  * as that user. Also lock down security-restricted operations and
345  * arrange to make GUC variable changes local to this command.
346  */
347  GetUserIdAndSecContext(&save_userid, &save_sec_context);
348  SetUserIdAndSecContext(onerel->rd_rel->relowner,
349  save_sec_context | SECURITY_RESTRICTED_OPERATION);
350  save_nestlevel = NewGUCNestLevel();
351 
352  /* measure elapsed time iff autovacuum logging requires it */
353  if (IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
354  {
355  if (track_io_timing)
356  {
357  startreadtime = pgStatBlockReadTime;
358  startwritetime = pgStatBlockWriteTime;
359  }
360 
361  pg_rusage_init(&ru0);
362  if (params->log_min_duration >= 0)
363  starttime = GetCurrentTimestamp();
364  }
365 
366  /*
367  * Determine which columns to analyze
368  *
369  * Note that system attributes are never analyzed, so we just reject them
370  * at the lookup stage. We also reject duplicate column mentions. (We
371  * could alternatively ignore duplicates, but analyzing a column twice
372  * won't work; we'd end up making a conflicting update in pg_statistic.)
373  */
374  if (va_cols != NIL)
375  {
376  Bitmapset *unique_cols = NULL;
377  ListCell *le;
378 
379  vacattrstats = (VacAttrStats **) palloc(list_length(va_cols) *
380  sizeof(VacAttrStats *));
381  tcnt = 0;
382  foreach(le, va_cols)
383  {
384  char *col = strVal(lfirst(le));
385 
386  i = attnameAttNum(onerel, col, false);
387  if (i == InvalidAttrNumber)
388  ereport(ERROR,
389  (errcode(ERRCODE_UNDEFINED_COLUMN),
390  errmsg("column \"%s\" of relation \"%s\" does not exist",
391  col, RelationGetRelationName(onerel))));
392  if (bms_is_member(i, unique_cols))
393  ereport(ERROR,
394  (errcode(ERRCODE_DUPLICATE_COLUMN),
395  errmsg("column \"%s\" of relation \"%s\" appears more than once",
396  col, RelationGetRelationName(onerel))));
397  unique_cols = bms_add_member(unique_cols, i);
398 
399  vacattrstats[tcnt] = examine_attribute(onerel, i, NULL);
400  if (vacattrstats[tcnt] != NULL)
401  tcnt++;
402  }
403  attr_cnt = tcnt;
404  }
405  else
406  {
407  attr_cnt = onerel->rd_att->natts;
408  vacattrstats = (VacAttrStats **)
409  palloc(attr_cnt * sizeof(VacAttrStats *));
410  tcnt = 0;
411  for (i = 1; i <= attr_cnt; i++)
412  {
413  vacattrstats[tcnt] = examine_attribute(onerel, i, NULL);
414  if (vacattrstats[tcnt] != NULL)
415  tcnt++;
416  }
417  attr_cnt = tcnt;
418  }
419 
420  /*
421  * Open all indexes of the relation, and see if there are any analyzable
422  * columns in the indexes. We do not analyze index columns if there was
423  * an explicit column list in the ANALYZE command, however.
424  *
425  * If we are doing a recursive scan, we don't want to touch the parent's
426  * indexes at all. If we're processing a partitioned table, we need to
427  * know if there are any indexes, but we don't want to process them.
428  */
429  if (onerel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
430  {
431  List *idxs = RelationGetIndexList(onerel);
432 
433  Irel = NULL;
434  nindexes = 0;
435  hasindex = idxs != NIL;
436  list_free(idxs);
437  }
438  else if (!inh)
439  {
440  vac_open_indexes(onerel, AccessShareLock, &nindexes, &Irel);
441  hasindex = nindexes > 0;
442  }
443  else
444  {
445  Irel = NULL;
446  nindexes = 0;
447  hasindex = false;
448  }
449  indexdata = NULL;
450  if (nindexes > 0)
451  {
452  indexdata = (AnlIndexData *) palloc0(nindexes * sizeof(AnlIndexData));
453  for (ind = 0; ind < nindexes; ind++)
454  {
455  AnlIndexData *thisdata = &indexdata[ind];
456  IndexInfo *indexInfo;
457 
458  thisdata->indexInfo = indexInfo = BuildIndexInfo(Irel[ind]);
459  thisdata->tupleFract = 1.0; /* fix later if partial */
460  if (indexInfo->ii_Expressions != NIL && va_cols == NIL)
461  {
462  ListCell *indexpr_item = list_head(indexInfo->ii_Expressions);
463 
464  thisdata->vacattrstats = (VacAttrStats **)
465  palloc(indexInfo->ii_NumIndexAttrs * sizeof(VacAttrStats *));
466  tcnt = 0;
467  for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
468  {
469  int keycol = indexInfo->ii_IndexAttrNumbers[i];
470 
471  if (keycol == 0)
472  {
473  /* Found an index expression */
474  Node *indexkey;
475 
476  if (indexpr_item == NULL) /* shouldn't happen */
477  elog(ERROR, "too few entries in indexprs list");
478  indexkey = (Node *) lfirst(indexpr_item);
479  indexpr_item = lnext(indexInfo->ii_Expressions,
480  indexpr_item);
481  thisdata->vacattrstats[tcnt] =
482  examine_attribute(Irel[ind], i + 1, indexkey);
483  if (thisdata->vacattrstats[tcnt] != NULL)
484  tcnt++;
485  }
486  }
487  thisdata->attr_cnt = tcnt;
488  }
489  }
490  }
491 
492  /*
493  * Determine how many rows we need to sample, using the worst case from
494  * all analyzable columns. We use a lower bound of 100 rows to avoid
495  * possible overflow in Vitter's algorithm. (Note: that will also be the
496  * target in the corner case where there are no analyzable columns.)
497  */
498  targrows = 100;
499  for (i = 0; i < attr_cnt; i++)
500  {
501  if (targrows < vacattrstats[i]->minrows)
502  targrows = vacattrstats[i]->minrows;
503  }
504  for (ind = 0; ind < nindexes; ind++)
505  {
506  AnlIndexData *thisdata = &indexdata[ind];
507 
508  for (i = 0; i < thisdata->attr_cnt; i++)
509  {
510  if (targrows < thisdata->vacattrstats[i]->minrows)
511  targrows = thisdata->vacattrstats[i]->minrows;
512  }
513  }
514 
515  /*
516  * Look at extended statistics objects too, as those may define custom
517  * statistics target. So we may need to sample more rows and then build
518  * the statistics with enough detail.
519  */
520  minrows = ComputeExtStatisticsRows(onerel, attr_cnt, vacattrstats);
521 
522  if (targrows < minrows)
523  targrows = minrows;
524 
525  /*
526  * Acquire the sample rows
527  */
528  rows = (HeapTuple *) palloc(targrows * sizeof(HeapTuple));
532  if (inh)
533  numrows = acquire_inherited_sample_rows(onerel, elevel,
534  rows, targrows,
535  &totalrows, &totaldeadrows);
536  else
537  numrows = (*acquirefunc) (onerel, elevel,
538  rows, targrows,
539  &totalrows, &totaldeadrows);
540 
541  /*
542  * Compute the statistics. Temporary results during the calculations for
543  * each column are stored in a child context. The calc routines are
544  * responsible to make sure that whatever they store into the VacAttrStats
545  * structure is allocated in anl_context.
546  */
547  if (numrows > 0)
548  {
549  MemoryContext col_context,
550  old_context;
551 
554 
555  col_context = AllocSetContextCreate(anl_context,
556  "Analyze Column",
558  old_context = MemoryContextSwitchTo(col_context);
559 
560  for (i = 0; i < attr_cnt; i++)
561  {
562  VacAttrStats *stats = vacattrstats[i];
563  AttributeOpts *aopt;
564 
565  stats->rows = rows;
566  stats->tupDesc = onerel->rd_att;
567  stats->compute_stats(stats,
569  numrows,
570  totalrows);
571 
572  /*
573  * If the appropriate flavor of the n_distinct option is
574  * specified, override with the corresponding value.
575  */
576  aopt = get_attribute_options(onerel->rd_id, stats->attr->attnum);
577  if (aopt != NULL)
578  {
579  float8 n_distinct;
580 
581  n_distinct = inh ? aopt->n_distinct_inherited : aopt->n_distinct;
582  if (n_distinct != 0.0)
583  stats->stadistinct = n_distinct;
584  }
585 
587  }
588 
589  if (nindexes > 0)
590  compute_index_stats(onerel, totalrows,
591  indexdata, nindexes,
592  rows, numrows,
593  col_context);
594 
595  MemoryContextSwitchTo(old_context);
596  MemoryContextDelete(col_context);
597 
598  /*
599  * Emit the completed stats rows into pg_statistic, replacing any
600  * previous statistics for the target columns. (If there are stats in
601  * pg_statistic for columns we didn't process, we leave them alone.)
602  */
603  update_attstats(RelationGetRelid(onerel), inh,
604  attr_cnt, vacattrstats);
605 
606  for (ind = 0; ind < nindexes; ind++)
607  {
608  AnlIndexData *thisdata = &indexdata[ind];
609 
610  update_attstats(RelationGetRelid(Irel[ind]), false,
611  thisdata->attr_cnt, thisdata->vacattrstats);
612  }
613 
614  /*
615  * Build extended statistics (if there are any).
616  *
617  * For now we only build extended statistics on individual relations,
618  * not for relations representing inheritance trees.
619  */
620  if (!inh)
621  BuildRelationExtStatistics(onerel, totalrows, numrows, rows,
622  attr_cnt, vacattrstats);
623  }
624 
627 
628  /*
629  * Update pages/tuples stats in pg_class ... but not if we're doing
630  * inherited stats.
631  *
632  * We assume that VACUUM hasn't set pg_class.reltuples already, even
633  * during a VACUUM ANALYZE. Although VACUUM often updates pg_class,
634  * exceptions exist. A "VACUUM (ANALYZE, INDEX_CLEANUP OFF)" command will
635  * never update pg_class entries for index relations. It's also possible
636  * that an individual index's pg_class entry won't be updated during
637  * VACUUM if the index AM returns NULL from its amvacuumcleanup() routine.
638  */
639  if (!inh)
640  {
641  BlockNumber relallvisible;
642 
643  visibilitymap_count(onerel, &relallvisible, NULL);
644 
645  /* Update pg_class for table relation */
646  vac_update_relstats(onerel,
647  relpages,
648  totalrows,
649  relallvisible,
650  hasindex,
653  in_outer_xact);
654 
655  /* Same for indexes */
656  for (ind = 0; ind < nindexes; ind++)
657  {
658  AnlIndexData *thisdata = &indexdata[ind];
659  double totalindexrows;
660 
661  totalindexrows = ceil(thisdata->tupleFract * totalrows);
662  vac_update_relstats(Irel[ind],
663  RelationGetNumberOfBlocks(Irel[ind]),
664  totalindexrows,
665  0,
666  false,
669  in_outer_xact);
670  }
671  }
672  else if (onerel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
673  {
674  /*
675  * Partitioned tables don't have storage, so we don't set any fields
676  * in their pg_class entries except for reltuples and relhasindex.
677  */
678  vac_update_relstats(onerel, -1, totalrows,
679  0, hasindex, InvalidTransactionId,
681  in_outer_xact);
682  }
683 
684  /*
685  * Now report ANALYZE to the stats collector. For regular tables, we do
686  * it only if not doing inherited stats. For partitioned tables, we only
687  * do it for inherited stats. (We're never called for not-inherited stats
688  * on partitioned tables anyway.)
689  *
690  * Reset the changes_since_analyze counter only if we analyzed all
691  * columns; otherwise, there is still work for auto-analyze to do.
692  */
693  if (!inh)
694  pgstat_report_analyze(onerel, totalrows, totaldeadrows,
695  (va_cols == NIL));
696  else if (onerel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
697  pgstat_report_analyze(onerel, 0, 0, (va_cols == NIL));
698 
699  /*
700  * If this isn't part of VACUUM ANALYZE, let index AMs do cleanup.
701  *
702  * Note that most index AMs perform a no-op as a matter of policy for
703  * amvacuumcleanup() when called in ANALYZE-only mode. The only exception
704  * among core index AMs is GIN/ginvacuumcleanup().
705  */
706  if (!(params->options & VACOPT_VACUUM))
707  {
708  for (ind = 0; ind < nindexes; ind++)
709  {
710  IndexBulkDeleteResult *stats;
711  IndexVacuumInfo ivinfo;
712 
713  ivinfo.index = Irel[ind];
714  ivinfo.analyze_only = true;
715  ivinfo.estimated_count = true;
716  ivinfo.message_level = elevel;
717  ivinfo.num_heap_tuples = onerel->rd_rel->reltuples;
718  ivinfo.strategy = vac_strategy;
719 
720  stats = index_vacuum_cleanup(&ivinfo, NULL);
721 
722  if (stats)
723  pfree(stats);
724  }
725  }
726 
727  /* Done with indexes */
728  vac_close_indexes(nindexes, Irel, NoLock);
729 
730  /* Log the action if appropriate */
731  if (IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
732  {
733  TimestampTz endtime = GetCurrentTimestamp();
734 
735  if (params->log_min_duration == 0 ||
736  TimestampDifferenceExceeds(starttime, endtime,
737  params->log_min_duration))
738  {
739  long delay_in_ms;
740  double read_rate = 0;
741  double write_rate = 0;
743 
744  /*
745  * Calculate the difference in the Page Hit/Miss/Dirty that
746  * happened as part of the analyze by subtracting out the
747  * pre-analyze values which we saved above.
748  */
749  AnalyzePageHit = VacuumPageHit - AnalyzePageHit;
750  AnalyzePageMiss = VacuumPageMiss - AnalyzePageMiss;
751  AnalyzePageDirty = VacuumPageDirty - AnalyzePageDirty;
752 
753  /*
754  * We do not expect an analyze to take > 25 days and it simplifies
755  * things a bit to use TimestampDifferenceMilliseconds.
756  */
757  delay_in_ms = TimestampDifferenceMilliseconds(starttime, endtime);
758 
759  /*
760  * Note that we are reporting these read/write rates in the same
761  * manner as VACUUM does, which means that while the 'average read
762  * rate' here actually corresponds to page misses and resulting
763  * reads which are also picked up by track_io_timing, if enabled,
764  * the 'average write rate' is actually talking about the rate of
765  * pages being dirtied, not being written out, so it's typical to
766  * have a non-zero 'avg write rate' while I/O timings only reports
767  * reads.
768  *
769  * It's not clear that an ANALYZE will ever result in
770  * FlushBuffer() being called, but we track and support reporting
771  * on I/O write time in case that changes as it's practically free
772  * to do so anyway.
773  */
774 
775  if (delay_in_ms > 0)
776  {
777  read_rate = (double) BLCKSZ * AnalyzePageMiss / (1024 * 1024) /
778  (delay_in_ms / 1000.0);
779  write_rate = (double) BLCKSZ * AnalyzePageDirty / (1024 * 1024) /
780  (delay_in_ms / 1000.0);
781  }
782 
783  /*
784  * We split this up so we don't emit empty I/O timing values when
785  * track_io_timing isn't enabled.
786  */
787 
788  initStringInfo(&buf);
789  appendStringInfo(&buf, _("automatic analyze of table \"%s.%s.%s\"\n"),
792  RelationGetRelationName(onerel));
793  if (track_io_timing)
794  {
795  double read_ms = (double) (pgStatBlockReadTime - startreadtime) / 1000;
796  double write_ms = (double) (pgStatBlockWriteTime - startwritetime) / 1000;
797 
798  appendStringInfo(&buf, _("I/O timings: read: %.3f ms, write: %.3f ms\n"),
799  read_ms, write_ms);
800  }
801  appendStringInfo(&buf, _("avg read rate: %.3f MB/s, avg write rate: %.3f MB/s\n"),
802  read_rate, write_rate);
803  appendStringInfo(&buf, _("buffer usage: %lld hits, %lld misses, %lld dirtied\n"),
804  (long long) AnalyzePageHit,
805  (long long) AnalyzePageMiss,
806  (long long) AnalyzePageDirty);
807  appendStringInfo(&buf, _("system usage: %s"), pg_rusage_show(&ru0));
808 
809  ereport(LOG,
810  (errmsg_internal("%s", buf.data)));
811 
812  pfree(buf.data);
813  }
814  }
815 
816  /* Roll back any GUC changes executed by index functions */
817  AtEOXact_GUC(false, save_nestlevel);
818 
819  /* Restore userid and security context */
820  SetUserIdAndSecContext(save_userid, save_sec_context);
821 
822  /* Restore current context and release memory */
823  MemoryContextSwitchTo(caller_context);
825  anl_context = NULL;
826 }
AttributeOpts * get_attribute_options(Oid attrelid, int attnum)
Definition: attoptcache.c:103
#define NIL
Definition: pg_list.h:65
void vac_close_indexes(int nindexes, Relation *Irel, LOCKMODE lockmode)
Definition: vacuum.c:2128
int ComputeExtStatisticsRows(Relation onerel, int natts, VacAttrStats **vacattrstats)
static int acquire_inherited_sample_rows(Relation onerel, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows)
Definition: analyze.c:1380
int minrows
Definition: vacuum.h:135
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:218
#define AllocSetContextCreate
Definition: memutils.h:173
int64 VacuumPageMiss
Definition: globals.c:148
int64 PgStat_Counter
Definition: pgstat.h:92
#define PROGRESS_ANALYZE_PHASE
Definition: progress.h:38
#define SECURITY_RESTRICTED_OPERATION
Definition: miscadmin.h:312
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:322
void SetUserIdAndSecContext(Oid userid, int sec_context)
Definition: miscinit.c:607
IndexBulkDeleteResult * index_vacuum_cleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *istat)
Definition: indexam.c:712
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1580
int64 TimestampTz
Definition: timestamp.h:39
HeapTuple * rows
Definition: vacuum.h:170
bool analyze_only
Definition: genam.h:47
int64 VacuumPageHit
Definition: globals.c:147
void pgstat_report_analyze(Relation rel, PgStat_Counter livetuples, PgStat_Counter deadtuples, bool resetcounter)
Definition: pgstat.c:1606
BufferAccessStrategy strategy
Definition: genam.h:52
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
#define AccessShareLock
Definition: lockdefs.h:36
Definition: nodes.h:536
#define strVal(v)
Definition: value.h:65
int errcode(int sqlerrcode)
Definition: elog.c:698
Relation index
Definition: genam.h:46
static BufferAccessStrategy vac_strategy
Definition: analyze.c:86
int64 VacuumPageDirty
Definition: globals.c:149
TupleDesc tupDesc
Definition: vacuum.h:171
uint32 BlockNumber
Definition: block.h:31
static void update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
Definition: analyze.c:1625
IndexInfo * BuildIndexInfo(Relation index)
Definition: index.c:2378
void visibilitymap_count(Relation rel, BlockNumber *all_visible, BlockNumber *all_frozen)
#define LOG
Definition: elog.h:26
Form_pg_class rd_rel
Definition: rel.h:109
unsigned int Oid
Definition: postgres_ext.h:31
bool TimestampDifferenceExceeds(TimestampTz start_time, TimestampTz stop_time, int msec)
Definition: timestamp.c:1711
#define PROGRESS_ANALYZE_PHASE_COMPUTE_STATS
Definition: progress.h:50
float8 n_distinct
Definition: attoptcache.h:22
Form_pg_attribute attr
Definition: vacuum.h:123
int attr_cnt
Definition: analyze.c:77
void pg_rusage_init(PGRUsage *ru0)
Definition: pg_rusage.c:27
bits32 options
Definition: vacuum.h:211
void pfree(void *pointer)
Definition: mcxt.c:1169
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:91
#define ERROR
Definition: elog.h:46
double float8
Definition: c.h:565
PgStat_Counter pgStatBlockWriteTime
Definition: pgstat.c:248
void BuildRelationExtStatistics(Relation onerel, double totalrows, int numrows, HeapTuple *rows, int natts, VacAttrStats **vacattrstats)
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:195
char * get_database_name(Oid dbid)
Definition: dbcommands.c:2113
static MemoryContext anl_context
Definition: analyze.c:85
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3316
PgStat_Counter pgStatBlockReadTime
Definition: pgstat.c:247
#define NoLock
Definition: lockdefs.h:34
static char * buf
Definition: pg_test_fsync.c:68
float8 n_distinct_inherited
Definition: attoptcache.h:23
void GetUserIdAndSecContext(Oid *userid, int *sec_context)
Definition: miscinit.c:600
void AtEOXact_GUC(bool isCommit, int nestLevel)
Definition: guc.c:6242
const char * pg_rusage_show(const PGRUsage *ru0)
Definition: pg_rusage.c:40
#define InvalidTransactionId
Definition: transam.h:31
#define RelationGetRelationName(relation)
Definition: rel.h:511
static ListCell * list_head(const List *l)
Definition: pg_list.h:125
MemoryContext CurrentMemoryContext
Definition: mcxt.c:42
bool IsAutoVacuumWorkerProcess(void)
Definition: autovacuum.c:3410
#define PROGRESS_ANALYZE_PHASE_FINALIZE_ANALYZE
Definition: progress.h:52
void initStringInfo(StringInfo str)
Definition: stringinfo.c:59
void vac_open_indexes(Relation relation, LOCKMODE lockmode, int *nindexes, Relation **Irel)
Definition: vacuum.c:2085
#define PROGRESS_ANALYZE_PHASE_ACQUIRE_SAMPLE_ROWS_INH
Definition: progress.h:49
static int elevel
Definition: vacuumlazy.c:401
#define MemoryContextResetAndDeleteChildren(ctx)
Definition: memutils.h:67
void * palloc0(Size size)
Definition: mcxt.c:1093
int ii_NumIndexAttrs
Definition: execnodes.h:159
Oid MyDatabaseId
Definition: globals.c:88
#define InvalidMultiXactId
Definition: multixact.h:24
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:212
TupleDesc rd_att
Definition: rel.h:110
#define ereport(elevel,...)
Definition: elog.h:157
#define PROGRESS_ANALYZE_PHASE_ACQUIRE_SAMPLE_ROWS
Definition: progress.h:48
int message_level
Definition: genam.h:50
int errmsg_internal(const char *fmt,...)
Definition: elog.c:996
double num_heap_tuples
Definition: genam.h:51
int attnameAttNum(Relation rd, const char *attname, bool sysColOK)
static void compute_index_stats(Relation onerel, double totalrows, AnlIndexData *indexdata, int nindexes, HeapTuple *rows, int numrows, MemoryContext col_context)
Definition: analyze.c:832
List * ii_Expressions
Definition: execnodes.h:162
#define VACOPT_VACUUM
Definition: vacuum.h:178
#define lfirst(lc)
Definition: pg_list.h:169
void pgstat_progress_update_param(int index, int64 val)
static int list_length(const List *l)
Definition: pg_list.h:149
int log_min_duration
Definition: vacuum.h:219
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:736
List * RelationGetIndexList(Relation relation)
Definition: relcache.c:4573
double tupleFract
Definition: analyze.c:75
#define InvalidAttrNumber
Definition: attnum.h:23
int NewGUCNestLevel(void)
Definition: guc.c:6228
void * palloc(Size size)
Definition: mcxt.c:1062
int errmsg(const char *fmt,...)
Definition: elog.c:909
VacAttrStats ** vacattrstats
Definition: analyze.c:76
void list_free(List *list)
Definition: list.c:1391
#define elog(elevel,...)
Definition: elog.h:232
int i
AnalyzeAttrComputeStatsFunc compute_stats
Definition: vacuum.h:134
AttrNumber ii_IndexAttrNumbers[INDEX_MAX_KEYS]
Definition: execnodes.h:161
void vac_update_relstats(Relation relation, BlockNumber num_pages, double num_tuples, BlockNumber num_all_visible_pages, bool hasindex, TransactionId frozenxid, MultiXactId minmulti, bool in_outer_xact)
Definition: vacuum.c:1306
Definition: pg_list.h:50
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:427
static VacAttrStats * examine_attribute(Relation onerel, int attnum, Node *index_expr)
Definition: analyze.c:1003
#define _(x)
Definition: elog.c:89
#define RelationGetRelid(relation)
Definition: rel.h:477
bool track_io_timing
Definition: bufmgr.c:135
long TimestampDifferenceMilliseconds(TimestampTz start_time, TimestampTz stop_time)
Definition: timestamp.c:1693
static Datum std_fetch_func(VacAttrStatsP stats, int rownum, bool *isNull)
Definition: analyze.c:1764
bool estimated_count
Definition: genam.h:49
float4 stadistinct
Definition: vacuum.h:145
IndexInfo * indexInfo
Definition: analyze.c:74
#define RelationGetNamespace(relation)
Definition: rel.h:518

◆ examine_attribute()

static VacAttrStats * examine_attribute ( Relation  onerel,
int  attnum,
Node index_expr 
)
static

Definition at line 1003 of file analyze.c.

References anl_context, VacAttrStats::anl_context, attnum, VacAttrStats::attr, VacAttrStats::attrcollid, ATTRIBUTE_FIXED_PART_SIZE, VacAttrStats::attrtype, VacAttrStats::attrtypid, VacAttrStats::attrtypmod, VacAttrStats::compute_stats, DatumGetBool, elog, ERROR, exprCollation(), exprType(), exprTypmod(), GETSTRUCT, heap_freetuple(), HeapTupleIsValid, i, VacAttrStats::minrows, ObjectIdGetDatum, OidFunctionCall1, OidIsValid, palloc(), palloc0(), pfree(), PointerGetDatum, RelationData::rd_att, RelationData::rd_indcollation, SearchSysCacheCopy1, STATISTIC_NUM_SLOTS, VacAttrStats::statypalign, VacAttrStats::statypbyval, VacAttrStats::statypid, VacAttrStats::statyplen, std_typanalyze(), VacAttrStats::tupattnum, TupleDescAttr, and TYPEOID.

Referenced by do_analyze_rel().

1004 {
1005  Form_pg_attribute attr = TupleDescAttr(onerel->rd_att, attnum - 1);
1006  HeapTuple typtuple;
1007  VacAttrStats *stats;
1008  int i;
1009  bool ok;
1010 
1011  /* Never analyze dropped columns */
1012  if (attr->attisdropped)
1013  return NULL;
1014 
1015  /* Don't analyze column if user has specified not to */
1016  if (attr->attstattarget == 0)
1017  return NULL;
1018 
1019  /*
1020  * Create the VacAttrStats struct. Note that we only have a copy of the
1021  * fixed fields of the pg_attribute tuple.
1022  */
1023  stats = (VacAttrStats *) palloc0(sizeof(VacAttrStats));
1025  memcpy(stats->attr, attr, ATTRIBUTE_FIXED_PART_SIZE);
1026 
1027  /*
1028  * When analyzing an expression index, believe the expression tree's type
1029  * not the column datatype --- the latter might be the opckeytype storage
1030  * type of the opclass, which is not interesting for our purposes. (Note:
1031  * if we did anything with non-expression index columns, we'd need to
1032  * figure out where to get the correct type info from, but for now that's
1033  * not a problem.) It's not clear whether anyone will care about the
1034  * typmod, but we store that too just in case.
1035  */
1036  if (index_expr)
1037  {
1038  stats->attrtypid = exprType(index_expr);
1039  stats->attrtypmod = exprTypmod(index_expr);
1040 
1041  /*
1042  * If a collation has been specified for the index column, use that in
1043  * preference to anything else; but if not, fall back to whatever we
1044  * can get from the expression.
1045  */
1046  if (OidIsValid(onerel->rd_indcollation[attnum - 1]))
1047  stats->attrcollid = onerel->rd_indcollation[attnum - 1];
1048  else
1049  stats->attrcollid = exprCollation(index_expr);
1050  }
1051  else
1052  {
1053  stats->attrtypid = attr->atttypid;
1054  stats->attrtypmod = attr->atttypmod;
1055  stats->attrcollid = attr->attcollation;
1056  }
1057 
1058  typtuple = SearchSysCacheCopy1(TYPEOID,
1059  ObjectIdGetDatum(stats->attrtypid));
1060  if (!HeapTupleIsValid(typtuple))
1061  elog(ERROR, "cache lookup failed for type %u", stats->attrtypid);
1062  stats->attrtype = (Form_pg_type) GETSTRUCT(typtuple);
1063  stats->anl_context = anl_context;
1064  stats->tupattnum = attnum;
1065 
1066  /*
1067  * The fields describing the stats->stavalues[n] element types default to
1068  * the type of the data being analyzed, but the type-specific typanalyze
1069  * function can change them if it wants to store something else.
1070  */
1071  for (i = 0; i < STATISTIC_NUM_SLOTS; i++)
1072  {
1073  stats->statypid[i] = stats->attrtypid;
1074  stats->statyplen[i] = stats->attrtype->typlen;
1075  stats->statypbyval[i] = stats->attrtype->typbyval;
1076  stats->statypalign[i] = stats->attrtype->typalign;
1077  }
1078 
1079  /*
1080  * Call the type-specific typanalyze function. If none is specified, use
1081  * std_typanalyze().
1082  */
1083  if (OidIsValid(stats->attrtype->typanalyze))
1084  ok = DatumGetBool(OidFunctionCall1(stats->attrtype->typanalyze,
1085  PointerGetDatum(stats)));
1086  else
1087  ok = std_typanalyze(stats);
1088 
1089  if (!ok || stats->compute_stats == NULL || stats->minrows <= 0)
1090  {
1091  heap_freetuple(typtuple);
1092  pfree(stats->attr);
1093  pfree(stats);
1094  return NULL;
1095  }
1096 
1097  return stats;
1098 }
int minrows
Definition: vacuum.h:135
#define GETSTRUCT(TUP)
Definition: htup_details.h:654
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:267
#define PointerGetDatum(X)
Definition: postgres.h:600
#define TupleDescAttr(tupdesc, i)
Definition: tupdesc.h:92
int tupattnum
Definition: vacuum.h:169
bool std_typanalyze(VacAttrStats *stats)
Definition: analyze.c:1857
bool statypbyval[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:162
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
int32 attrtypmod
Definition: vacuum.h:125
#define OidIsValid(objectId)
Definition: c.h:710
char statypalign[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:163
Form_pg_attribute attr
Definition: vacuum.h:123
void pfree(void *pointer)
Definition: mcxt.c:1169
Oid attrtypid
Definition: vacuum.h:124
Oid * rd_indcollation
Definition: rel.h:212
#define ObjectIdGetDatum(X)
Definition: postgres.h:551
#define ERROR
Definition: elog.h:46
#define OidFunctionCall1(functionId, arg1)
Definition: fmgr.h:664
static MemoryContext anl_context
Definition: analyze.c:85
#define DatumGetBool(X)
Definition: postgres.h:437
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:207
#define ATTRIBUTE_FIXED_PART_SIZE
Definition: pg_attribute.h:199
void * palloc0(Size size)
Definition: mcxt.c:1093
TupleDesc rd_att
Definition: rel.h:110
Oid statypid[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:160
int16 attnum
Definition: pg_attribute.h:83
#define STATISTIC_NUM_SLOTS
Definition: pg_statistic.h:127
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:41
FormData_pg_type * Form_pg_type
Definition: pg_type.h:261
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:759
Oid attrcollid
Definition: vacuum.h:127
MemoryContext anl_context
Definition: vacuum.h:128
#define SearchSysCacheCopy1(cacheId, key1)
Definition: syscache.h:175
Form_pg_type attrtype
Definition: vacuum.h:126
void * palloc(Size size)
Definition: mcxt.c:1062
int16 statyplen[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:161
#define elog(elevel,...)
Definition: elog.h:232
int i
AnalyzeAttrComputeStatsFunc compute_stats
Definition: vacuum.h:134

◆ ind_fetch_func()

static Datum ind_fetch_func ( VacAttrStatsP  stats,
int  rownum,
bool isNull 
)
static

Definition at line 1780 of file analyze.c.

References VacAttrStats::exprnulls, VacAttrStats::exprvals, i, and VacAttrStats::rowstride.

Referenced by compute_index_stats().

1781 {
1782  int i;
1783 
1784  /* exprvals and exprnulls are already offset for proper column */
1785  i = rownum * stats->rowstride;
1786  *isNull = stats->exprnulls[i];
1787  return stats->exprvals[i];
1788 }
int rowstride
Definition: vacuum.h:174
bool * exprnulls
Definition: vacuum.h:173
Datum * exprvals
Definition: vacuum.h:172
int i

◆ std_fetch_func()

static Datum std_fetch_func ( VacAttrStatsP  stats,
int  rownum,
bool isNull 
)
static

Definition at line 1764 of file analyze.c.

References attnum, heap_getattr, VacAttrStats::rows, VacAttrStats::tupattnum, and VacAttrStats::tupDesc.

Referenced by do_analyze_rel().

1765 {
1766  int attnum = stats->tupattnum;
1767  HeapTuple tuple = stats->rows[rownum];
1768  TupleDesc tupDesc = stats->tupDesc;
1769 
1770  return heap_getattr(tuple, attnum, tupDesc, isNull);
1771 }
HeapTuple * rows
Definition: vacuum.h:170
int tupattnum
Definition: vacuum.h:169
TupleDesc tupDesc
Definition: vacuum.h:171
#define heap_getattr(tup, attnum, tupleDesc, isnull)
Definition: htup_details.h:761
int16 attnum
Definition: pg_attribute.h:83

◆ std_typanalyze()

bool std_typanalyze ( VacAttrStats stats)

Definition at line 1857 of file analyze.c.

References VacAttrStats::attr, VacAttrStats::attrtypid, compute_distinct_stats(), compute_scalar_stats(), VacAttrStats::compute_stats, compute_trivial_stats(), default_statistics_target, StdAnalyzeData::eqfunc, StdAnalyzeData::eqopr, VacAttrStats::extra_data, get_opcode(), get_sort_group_operators(), InvalidOid, StdAnalyzeData::ltopr, VacAttrStats::minrows, OidIsValid, and palloc().

Referenced by array_typanalyze(), examine_attribute(), and examine_expression().

1858 {
1859  Form_pg_attribute attr = stats->attr;
1860  Oid ltopr;
1861  Oid eqopr;
1862  StdAnalyzeData *mystats;
1863 
1864  /* If the attstattarget column is negative, use the default value */
1865  /* NB: it is okay to scribble on stats->attr since it's a copy */
1866  if (attr->attstattarget < 0)
1867  attr->attstattarget = default_statistics_target;
1868 
1869  /* Look for default "<" and "=" operators for column's type */
1871  false, false, false,
1872  &ltopr, &eqopr, NULL,
1873  NULL);
1874 
1875  /* Save the operator info for compute_stats routines */
1876  mystats = (StdAnalyzeData *) palloc(sizeof(StdAnalyzeData));
1877  mystats->eqopr = eqopr;
1878  mystats->eqfunc = OidIsValid(eqopr) ? get_opcode(eqopr) : InvalidOid;
1879  mystats->ltopr = ltopr;
1880  stats->extra_data = mystats;
1881 
1882  /*
1883  * Determine which standard statistics algorithm to use
1884  */
1885  if (OidIsValid(eqopr) && OidIsValid(ltopr))
1886  {
1887  /* Seems to be a scalar datatype */
1889  /*--------------------
1890  * The following choice of minrows is based on the paper
1891  * "Random sampling for histogram construction: how much is enough?"
1892  * by Surajit Chaudhuri, Rajeev Motwani and Vivek Narasayya, in
1893  * Proceedings of ACM SIGMOD International Conference on Management
1894  * of Data, 1998, Pages 436-447. Their Corollary 1 to Theorem 5
1895  * says that for table size n, histogram size k, maximum relative
1896  * error in bin size f, and error probability gamma, the minimum
1897  * random sample size is
1898  * r = 4 * k * ln(2*n/gamma) / f^2
1899  * Taking f = 0.5, gamma = 0.01, n = 10^6 rows, we obtain
1900  * r = 305.82 * k
1901  * Note that because of the log function, the dependence on n is
1902  * quite weak; even at n = 10^12, a 300*k sample gives <= 0.66
1903  * bin size error with probability 0.99. So there's no real need to
1904  * scale for n, which is a good thing because we don't necessarily
1905  * know it at this point.
1906  *--------------------
1907  */
1908  stats->minrows = 300 * attr->attstattarget;
1909  }
1910  else if (OidIsValid(eqopr))
1911  {
1912  /* We can still recognize distinct values */
1914  /* Might as well use the same minrows as above */
1915  stats->minrows = 300 * attr->attstattarget;
1916  }
1917  else
1918  {
1919  /* Can't do much but the trivial stuff */
1921  /* Might as well use the same minrows as above */
1922  stats->minrows = 300 * attr->attstattarget;
1923  }
1924 
1925  return true;
1926 }
int minrows
Definition: vacuum.h:135
static void compute_scalar_stats(VacAttrStatsP stats, AnalyzeAttrFetchFunc fetchfunc, int samplerows, double totalrows)
Definition: analyze.c:2370
unsigned int Oid
Definition: postgres_ext.h:31
#define OidIsValid(objectId)
Definition: c.h:710
Form_pg_attribute attr
Definition: vacuum.h:123
Oid attrtypid
Definition: vacuum.h:124
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:207
static void compute_distinct_stats(VacAttrStatsP stats, AnalyzeAttrFetchFunc fetchfunc, int samplerows, double totalrows)
Definition: analyze.c:2027
#define InvalidOid
Definition: postgres_ext.h:36
RegProcedure get_opcode(Oid opno)
Definition: lsyscache.c:1256
void get_sort_group_operators(Oid argtype, bool needLT, bool needEQ, bool needGT, Oid *ltOpr, Oid *eqOpr, Oid *gtOpr, bool *isHashable)
Definition: parse_oper.c:192
static void compute_trivial_stats(VacAttrStatsP stats, AnalyzeAttrFetchFunc fetchfunc, int samplerows, double totalrows)
Definition: analyze.c:1937
void * palloc(Size size)
Definition: mcxt.c:1062
AnalyzeAttrComputeStatsFunc compute_stats
Definition: vacuum.h:134
void * extra_data
Definition: vacuum.h:136
int default_statistics_target
Definition: analyze.c:82

◆ update_attstats()

static void update_attstats ( Oid  relid,
bool  inh,
int  natts,
VacAttrStats **  vacattrstats 
)
static

Definition at line 1625 of file analyze.c.

References VacAttrStats::attr, BoolGetDatum, CatalogTupleInsert(), CatalogTupleUpdate(), construct_array(), Float4GetDatum(), heap_form_tuple(), heap_freetuple(), heap_modify_tuple(), HeapTupleIsValid, i, Int16GetDatum, Int32GetDatum, VacAttrStats::numnumbers, VacAttrStats::numvalues, ObjectIdGetDatum, palloc(), PointerGetDatum, RelationGetDescr, ReleaseSysCache(), RowExclusiveLock, SearchSysCache3(), VacAttrStats::stacoll, VacAttrStats::stadistinct, VacAttrStats::stakind, VacAttrStats::stanullfrac, VacAttrStats::stanumbers, VacAttrStats::staop, STATISTIC_NUM_SLOTS, STATRELATTINH, VacAttrStats::stats_valid, VacAttrStats::statypalign, VacAttrStats::statypbyval, VacAttrStats::statypid, VacAttrStats::statyplen, VacAttrStats::stavalues, VacAttrStats::stawidth, HeapTupleData::t_self, table_close(), table_open(), and values.

Referenced by do_analyze_rel().

1626 {
1627  Relation sd;
1628  int attno;
1629 
1630  if (natts <= 0)
1631  return; /* nothing to do */
1632 
1633  sd = table_open(StatisticRelationId, RowExclusiveLock);
1634 
1635  for (attno = 0; attno < natts; attno++)
1636  {
1637  VacAttrStats *stats = vacattrstats[attno];
1638  HeapTuple stup,
1639  oldtup;
1640  int i,
1641  k,
1642  n;
1643  Datum values[Natts_pg_statistic];
1644  bool nulls[Natts_pg_statistic];
1645  bool replaces[Natts_pg_statistic];
1646 
1647  /* Ignore attr if we weren't able to collect stats */
1648  if (!stats->stats_valid)
1649  continue;
1650 
1651  /*
1652  * Construct a new pg_statistic tuple
1653  */
1654  for (i = 0; i < Natts_pg_statistic; ++i)
1655  {
1656  nulls[i] = false;
1657  replaces[i] = true;
1658  }
1659 
1660  values[Anum_pg_statistic_starelid - 1] = ObjectIdGetDatum(relid);
1661  values[Anum_pg_statistic_staattnum - 1] = Int16GetDatum(stats->attr->attnum);
1662  values[Anum_pg_statistic_stainherit - 1] = BoolGetDatum(inh);
1663  values[Anum_pg_statistic_stanullfrac - 1] = Float4GetDatum(stats->stanullfrac);
1664  values[Anum_pg_statistic_stawidth - 1] = Int32GetDatum(stats->stawidth);
1665  values[Anum_pg_statistic_stadistinct - 1] = Float4GetDatum(stats->stadistinct);
1666  i = Anum_pg_statistic_stakind1 - 1;
1667  for (k = 0; k < STATISTIC_NUM_SLOTS; k++)
1668  {
1669  values[i++] = Int16GetDatum(stats->stakind[k]); /* stakindN */
1670  }
1671  i = Anum_pg_statistic_staop1 - 1;
1672  for (k = 0; k < STATISTIC_NUM_SLOTS; k++)
1673  {
1674  values[i++] = ObjectIdGetDatum(stats->staop[k]); /* staopN */
1675  }
1676  i = Anum_pg_statistic_stacoll1 - 1;
1677  for (k = 0; k < STATISTIC_NUM_SLOTS; k++)
1678  {
1679  values[i++] = ObjectIdGetDatum(stats->stacoll[k]); /* stacollN */
1680  }
1681  i = Anum_pg_statistic_stanumbers1 - 1;
1682  for (k = 0; k < STATISTIC_NUM_SLOTS; k++)
1683  {
1684  int nnum = stats->numnumbers[k];
1685 
1686  if (nnum > 0)
1687  {
1688  Datum *numdatums = (Datum *) palloc(nnum * sizeof(Datum));
1689  ArrayType *arry;
1690 
1691  for (n = 0; n < nnum; n++)
1692  numdatums[n] = Float4GetDatum(stats->stanumbers[k][n]);
1693  /* XXX knows more than it should about type float4: */
1694  arry = construct_array(numdatums, nnum,
1695  FLOAT4OID,
1696  sizeof(float4), true, TYPALIGN_INT);
1697  values[i++] = PointerGetDatum(arry); /* stanumbersN */
1698  }
1699  else
1700  {
1701  nulls[i] = true;
1702  values[i++] = (Datum) 0;
1703  }
1704  }
1705  i = Anum_pg_statistic_stavalues1 - 1;
1706  for (k = 0; k < STATISTIC_NUM_SLOTS; k++)
1707  {
1708  if (stats->numvalues[k] > 0)
1709  {
1710  ArrayType *arry;
1711 
1712  arry = construct_array(stats->stavalues[k],
1713  stats->numvalues[k],
1714  stats->statypid[k],
1715  stats->statyplen[k],
1716  stats->statypbyval[k],
1717  stats->statypalign[k]);
1718  values[i++] = PointerGetDatum(arry); /* stavaluesN */
1719  }
1720  else
1721  {
1722  nulls[i] = true;
1723  values[i++] = (Datum) 0;
1724  }
1725  }
1726 
1727  /* Is there already a pg_statistic tuple for this attribute? */
1728  oldtup = SearchSysCache3(STATRELATTINH,
1729  ObjectIdGetDatum(relid),
1730  Int16GetDatum(stats->attr->attnum),
1731  BoolGetDatum(inh));
1732 
1733  if (HeapTupleIsValid(oldtup))
1734  {
1735  /* Yes, replace it */
1736  stup = heap_modify_tuple(oldtup,
1737  RelationGetDescr(sd),
1738  values,
1739  nulls,
1740  replaces);
1741  ReleaseSysCache(oldtup);
1742  CatalogTupleUpdate(sd, &stup->t_self, stup);
1743  }
1744  else
1745  {
1746  /* No, insert new tuple */
1747  stup = heap_form_tuple(RelationGetDescr(sd), values, nulls);
1748  CatalogTupleInsert(sd, stup);
1749  }
1750 
1751  heap_freetuple(stup);
1752  }
1753 
1755 }
static Datum Float4GetDatum(float4 X)
Definition: postgres.h:725
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:167
#define RelationGetDescr(relation)
Definition: rel.h:503
#define PointerGetDatum(X)
Definition: postgres.h:600
Datum * stavalues[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:152
#define Int16GetDatum(X)
Definition: postgres.h:495
ArrayType * construct_array(Datum *elems, int nelems, Oid elmtype, int elmlen, bool elmbyval, char elmalign)
Definition: arrayfuncs.c:3319
bool statypbyval[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:162
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: heaptuple.c:1020
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
char statypalign[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:163
Form_pg_attribute attr
Definition: vacuum.h:123
#define ObjectIdGetDatum(X)
Definition: postgres.h:551
int32 stawidth
Definition: vacuum.h:144
Oid stacoll[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:148
HeapTuple SearchSysCache3(int cacheId, Datum key1, Datum key2, Datum key3)
Definition: syscache.c:1149
ItemPointerData t_self
Definition: htup.h:65
int numnumbers[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:149
#define RowExclusiveLock
Definition: lockdefs.h:38
float4 stanullfrac
Definition: vacuum.h:143
Oid staop[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:147
bool stats_valid
Definition: vacuum.h:142
float float4
Definition: c.h:564
uintptr_t Datum
Definition: postgres.h:411
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:1175
int16 stakind[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:146
Oid statypid[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:160
#define BoolGetDatum(X)
Definition: postgres.h:446
#define STATISTIC_NUM_SLOTS
Definition: pg_statistic.h:127
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
float4 * stanumbers[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:150
void CatalogTupleUpdate(Relation heapRel, ItemPointer otid, HeapTuple tup)
Definition: indexing.c:301
static Datum values[MAXATTR]
Definition: bootstrap.c:156
#define Int32GetDatum(X)
Definition: postgres.h:523
int numvalues[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:151
void * palloc(Size size)
Definition: mcxt.c:1062
int16 statyplen[STATISTIC_NUM_SLOTS]
Definition: vacuum.h:161
int i
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:39
HeapTuple heap_modify_tuple(HeapTuple tuple, TupleDesc tupleDesc, Datum *replValues, bool *replIsnull, bool *doReplace)
Definition: heaptuple.c:1113
void CatalogTupleInsert(Relation heapRel, HeapTuple tup)
Definition: indexing.c:221
float4 stadistinct
Definition: vacuum.h:145

Variable Documentation

◆ anl_context

MemoryContext anl_context = NULL
static

Definition at line 85 of file analyze.c.

Referenced by examine_attribute().

◆ default_statistics_target

int default_statistics_target = 100

◆ vac_strategy

BufferAccessStrategy vac_strategy
static

Definition at line 86 of file analyze.c.

Referenced by do_analyze_rel().