nbtutils.c File Reference

#include "postgres.h"
#include <time.h>
#include "access/nbtree.h"
#include "access/reloptions.h"
#include "access/relscan.h"
#include "commands/progress.h"
#include "common/int.h"
#include "lib/qunique.h"
#include "miscadmin.h"
#include "storage/lwlock.h"
#include "storage/subsystems.h"
#include "utils/datum.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"

Include dependency graph for nbtutils.c:

Go to the source code of this file.

Data Structures
struct	BTOneVacInfo
struct	BTVacInfo

Typedefs
typedef struct BTOneVacInfo	BTOneVacInfo
typedef struct BTVacInfo	BTVacInfo

Functions
static int	_bt_compare_int (const void *va, const void *vb)
static int	_bt_keep_natts (Relation rel, IndexTuple lastleft, IndexTuple firstright, BTScanInsert itup_key)
BTScanInsert	_bt_mkscankey (Relation rel, IndexTuple itup)
void	_bt_killitems (IndexScanDesc scan)
static void	BTreeShmemRequest (void *arg)
static void	BTreeShmemInit (void *arg)
BTCycleId	_bt_vacuum_cycleid (Relation rel)
BTCycleId	_bt_start_vacuum (Relation rel)
void	_bt_end_vacuum (Relation rel)
void	_bt_end_vacuum_callback (int code, Datum arg)
bytea *	btoptions (Datum reloptions, bool validate)
bool	btproperty (Oid index_oid, int attno, IndexAMProperty prop, const char *propname, bool *res, bool *isnull)
char *	btbuildphasename (int64 phasenum)
IndexTuple	_bt_truncate (Relation rel, IndexTuple lastleft, IndexTuple firstright, BTScanInsert itup_key)
int	_bt_keep_natts_fast (Relation rel, IndexTuple lastleft, IndexTuple firstright)
bool	_bt_check_natts (Relation rel, bool heapkeyspace, Page page, OffsetNumber offnum)
void	_bt_check_third_page (Relation rel, Relation heap, bool needheaptidspace, Page page, IndexTuple newtup)
bool	_bt_allequalimage (Relation rel, bool debugmessage)

Variables
static BTVacInfo *	btvacinfo
const ShmemCallbacks	BTreeShmemCallbacks

Typedef Documentation

BTOneVacInfo

typedef struct BTOneVacInfo BTOneVacInfo

BTVacInfo

typedef struct BTVacInfo BTVacInfo

Function Documentation

_bt_allequalimage()

bool _bt_allequalimage	(	Relation	rel,
		bool	debugmessage
	)

Definition at line 1175 of file nbtutils.c.

{
    bool        allequalimage = true;
 
    /* INCLUDE indexes can never support deduplication */
    if (IndexRelationGetNumberOfAttributes(rel) !=
        IndexRelationGetNumberOfKeyAttributes(rel))
        return false;
 
    for (int i = 0; i < IndexRelationGetNumberOfKeyAttributes(rel); i++)
    {
        Oid         opfamily = rel->rd_opfamily[i];
        Oid         opcintype = rel->rd_opcintype[i];
        Oid         collation = rel->rd_indcollation[i];
        Oid         equalimageproc;
 
        equalimageproc = get_opfamily_proc(opfamily, opcintype, opcintype,
                                           BTEQUALIMAGE_PROC);
 
        /*
         * If there is no BTEQUALIMAGE_PROC then deduplication is assumed to
         * be unsafe.  Otherwise, actually call proc and see what it says.
         */
        if (!OidIsValid(equalimageproc) ||
            !DatumGetBool(OidFunctionCall1Coll(equalimageproc, collation,
                                               ObjectIdGetDatum(opcintype))))
        {
            allequalimage = false;
            break;
        }
    }
 
    if (debugmessage)
    {
        if (allequalimage)
            elog(DEBUG1, "index \"%s\" can safely use deduplication",
                 RelationGetRelationName(rel));
        else
            elog(DEBUG1, "index \"%s\" cannot use deduplication",
                 RelationGetRelationName(rel));
    }
 
    return allequalimage;
}

References BTEQUALIMAGE_PROC, DatumGetBool(), DEBUG1, elog, fb(), get_opfamily_proc(), i, IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, ObjectIdGetDatum(), OidFunctionCall1Coll(), OidIsValid, RelationData::rd_indcollation, RelationData::rd_opcintype, RelationData::rd_opfamily, and RelationGetRelationName.

Referenced by _bt_leafbuild(), bt_index_check_callback(), and btbuildempty().

_bt_check_natts()

bool _bt_check_natts	(	Relation	rel,
		bool	heapkeyspace,
		Page	page,
		OffsetNumber	offnum
	)

Definition at line 958 of file nbtutils.c.

{
    int16       natts = IndexRelationGetNumberOfAttributes(rel);
    int16       nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    BTPageOpaque opaque = BTPageGetOpaque(page);
    IndexTuple  itup;
    int         tupnatts;
 
    /*
     * We cannot reliably test a deleted or half-dead page, since they have
     * dummy high keys
     */
    if (P_IGNORE(opaque))
        return true;
 
    Assert(offnum >= FirstOffsetNumber &&
           offnum <= PageGetMaxOffsetNumber(page));
 
    itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, offnum));
    tupnatts = BTreeTupleGetNAtts(itup, rel);
 
    /* !heapkeyspace indexes do not support deduplication */
    if (!heapkeyspace && BTreeTupleIsPosting(itup))
        return false;
 
    /* Posting list tuples should never have "pivot heap TID" bit set */
    if (BTreeTupleIsPosting(itup) &&
        (ItemPointerGetOffsetNumberNoCheck(&itup->t_tid) &
         BT_PIVOT_HEAP_TID_ATTR) != 0)
        return false;
 
    /* INCLUDE indexes do not support deduplication */
    if (natts != nkeyatts && BTreeTupleIsPosting(itup))
        return false;
 
    if (P_ISLEAF(opaque))
    {
        if (offnum >= P_FIRSTDATAKEY(opaque))
        {
            /*
             * Non-pivot tuple should never be explicitly marked as a pivot
             * tuple
             */
            if (BTreeTupleIsPivot(itup))
                return false;
 
            /*
             * Leaf tuples that are not the page high key (non-pivot tuples)
             * should never be truncated.  (Note that tupnatts must have been
             * inferred, even with a posting list tuple, because only pivot
             * tuples store tupnatts directly.)
             */
            return tupnatts == natts;
        }
        else
        {
            /*
             * Rightmost page doesn't contain a page high key, so tuple was
             * checked above as ordinary leaf tuple
             */
            Assert(!P_RIGHTMOST(opaque));
 
            /*
             * !heapkeyspace high key tuple contains only key attributes. Note
             * that tupnatts will only have been explicitly represented in
             * !heapkeyspace indexes that happen to have non-key attributes.
             */
            if (!heapkeyspace)
                return tupnatts == nkeyatts;
 
            /* Use generic heapkeyspace pivot tuple handling */
        }
    }
    else                        /* !P_ISLEAF(opaque) */
    {
        if (offnum == P_FIRSTDATAKEY(opaque))
        {
            /*
             * The first tuple on any internal page (possibly the first after
             * its high key) is its negative infinity tuple.  Negative
             * infinity tuples are always truncated to zero attributes.  They
             * are a particular kind of pivot tuple.
             */
            if (heapkeyspace)
                return tupnatts == 0;
 
            /*
             * The number of attributes won't be explicitly represented if the
             * negative infinity tuple was generated during a page split that
             * occurred with a version of Postgres before v11.  There must be
             * a problem when there is an explicit representation that is
             * non-zero, or when there is no explicit representation and the
             * tuple is evidently not a pre-pg_upgrade tuple.
             *
             * Prior to v11, downlinks always had P_HIKEY as their offset.
             * Accept that as an alternative indication of a valid
             * !heapkeyspace negative infinity tuple.
             */
            return tupnatts == 0 ||
                ItemPointerGetOffsetNumber(&(itup->t_tid)) == P_HIKEY;
        }
        else
        {
            /*
             * !heapkeyspace downlink tuple with separator key contains only
             * key attributes.  Note that tupnatts will only have been
             * explicitly represented in !heapkeyspace indexes that happen to
             * have non-key attributes.
             */
            if (!heapkeyspace)
                return tupnatts == nkeyatts;
 
            /* Use generic heapkeyspace pivot tuple handling */
        }
    }
 
    /* Handle heapkeyspace pivot tuples (excluding minus infinity items) */
    Assert(heapkeyspace);
 
    /*
     * Explicit representation of the number of attributes is mandatory with
     * heapkeyspace index pivot tuples, regardless of whether or not there are
     * non-key attributes.
     */
    if (!BTreeTupleIsPivot(itup))
        return false;
 
    /* Pivot tuple should not use posting list representation (redundant) */
    if (BTreeTupleIsPosting(itup))
        return false;
 
    /*
     * Heap TID is a tiebreaker key attribute, so it cannot be untruncated
     * when any other key attribute is truncated
     */
    if (BTreeTupleGetHeapTID(itup) != NULL && tupnatts != nkeyatts)
        return false;
 
    /*
     * Pivot tuple must have at least one untruncated key attribute (minus
     * infinity pivot tuples are the only exception).  Pivot tuples can never
     * represent that there is a value present for a key attribute that
     * exceeds pg_index.indnkeyatts for the index.
     */
    return tupnatts > 0 && tupnatts <= nkeyatts;
}

References Assert, BT_PIVOT_HEAP_TID_ATTR, BTPageGetOpaque, BTreeTupleGetHeapTID(), BTreeTupleGetNAtts, BTreeTupleIsPivot(), BTreeTupleIsPosting(), fb(), FirstOffsetNumber, IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, ItemPointerGetOffsetNumber(), ItemPointerGetOffsetNumberNoCheck(), P_FIRSTDATAKEY, P_HIKEY, P_IGNORE, P_ISLEAF, P_RIGHTMOST, PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), and IndexTupleData::t_tid.

Referenced by _bt_compare(), and bt_target_page_check().

_bt_check_third_page()

void _bt_check_third_page	(	Relation	rel,
		Relation	heap,
		bool	needheaptidspace,
		Page	page,
		IndexTuple	newtup
	)

Definition at line 1118 of file nbtutils.c.

{
    Size        itemsz;
    BTPageOpaque opaque;
 
    itemsz = MAXALIGN(IndexTupleSize(newtup));
 
    /* Double check item size against limit */
    if (itemsz <= BTMaxItemSize)
        return;
 
    /*
     * Tuple is probably too large to fit on page, but it's possible that the
     * index uses version 2 or version 3, or that page is an internal page, in
     * which case a slightly higher limit applies.
     */
    if (!needheaptidspace && itemsz <= BTMaxItemSizeNoHeapTid)
        return;
 
    /*
     * Internal page insertions cannot fail here, because that would mean that
     * an earlier leaf level insertion that should have failed didn't
     */
    opaque = BTPageGetOpaque(page);
    if (!P_ISLEAF(opaque))
        elog(ERROR, "cannot insert oversized tuple of size %zu on internal page of index \"%s\"",
             itemsz, RelationGetRelationName(rel));
 
    ereport(ERROR,
            (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
             errmsg("index row size %zu exceeds btree version %u maximum %zu for index \"%s\"",
                    itemsz,
                    needheaptidspace ? BTREE_VERSION : BTREE_NOVAC_VERSION,
                    needheaptidspace ? BTMaxItemSize : BTMaxItemSizeNoHeapTid,
                    RelationGetRelationName(rel)),
             errdetail("Index row references tuple (%u,%u) in relation \"%s\".",
                       ItemPointerGetBlockNumber(BTreeTupleGetHeapTID(newtup)),
                       ItemPointerGetOffsetNumber(BTreeTupleGetHeapTID(newtup)),
                       RelationGetRelationName(heap)),
             errhint("Values larger than 1/3 of a buffer page cannot be indexed.\n"
                     "Consider a function index of an MD5 hash of the value, "
                     "or use full text indexing."),
             errtableconstraint(heap, RelationGetRelationName(rel))));
}

References BTMaxItemSize, BTMaxItemSizeNoHeapTid, BTPageGetOpaque, BTREE_NOVAC_VERSION, BTREE_VERSION, BTreeTupleGetHeapTID(), elog, ereport, errcode(), errdetail(), errhint(), errmsg, ERROR, errtableconstraint(), fb(), IndexTupleSize(), ItemPointerGetBlockNumber(), ItemPointerGetOffsetNumber(), MAXALIGN, P_ISLEAF, and RelationGetRelationName.

Referenced by _bt_buildadd(), and _bt_findinsertloc().

_bt_compare_int()

static int _bt_compare_int ( const void *  va, const void *  vb  )

static

Definition at line 153 of file nbtutils.c.

{
    int         a = *((const int *) va);
    int         b = *((const int *) vb);
 
    return pg_cmp_s32(a, b);
}

References a, b, fb(), and pg_cmp_s32().

Referenced by _bt_killitems().

_bt_end_vacuum()

void _bt_end_vacuum

(

Relation

rel

)

Definition at line 530 of file nbtutils.c.

{
    int         i;
 
    LWLockAcquire(BtreeVacuumLock, LW_EXCLUSIVE);
 
    /* Find the array entry */
    for (i = 0; i < btvacinfo->num_vacuums; i++)
    {
        BTOneVacInfo *vac = &btvacinfo->vacuums[i];
 
        if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
            vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId)
        {
            /* Remove it by shifting down the last entry */
            *vac = btvacinfo->vacuums[btvacinfo->num_vacuums - 1];
            btvacinfo->num_vacuums--;
            break;
        }
    }
 
    LWLockRelease(BtreeVacuumLock);
}

References btvacinfo, LockRelId::dbId, fb(), i, LockInfoData::lockRelId, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), BTVacInfo::num_vacuums, RelationData::rd_lockInfo, BTOneVacInfo::relid, LockRelId::relId, and BTVacInfo::vacuums.

Referenced by _bt_end_vacuum_callback(), and btbulkdelete().

_bt_end_vacuum_callback()

void _bt_end_vacuum_callback	(	int	code,
		Datum	arg
	)

Definition at line 558 of file nbtutils.c.

{
    _bt_end_vacuum((Relation) DatumGetPointer(arg));
}

References _bt_end_vacuum(), arg, and DatumGetPointer().

Referenced by btbulkdelete().

_bt_keep_natts()

static int _bt_keep_natts ( Relation  rel, IndexTuple  lastleft, IndexTuple  firstright, BTScanInsert  itup_key  )

static

Definition at line 837 of file nbtutils.c.

{
    int         nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    TupleDesc   itupdesc = RelationGetDescr(rel);
    int         keepnatts;
    ScanKey     scankey;
 
    /*
     * _bt_compare() treats truncated key attributes as having the value minus
     * infinity, which would break searches within !heapkeyspace indexes.  We
     * must still truncate away non-key attribute values, though.
     */
    if (!itup_key->heapkeyspace)
        return nkeyatts;
 
    scankey = itup_key->scankeys;
    keepnatts = 1;
    for (int attnum = 1; attnum <= nkeyatts; attnum++, scankey++)
    {
        Datum       datum1,
                    datum2;
        bool        isNull1,
                    isNull2;
 
        datum1 = index_getattr(lastleft, attnum, itupdesc, &isNull1);
        datum2 = index_getattr(firstright, attnum, itupdesc, &isNull2);
 
        if (isNull1 != isNull2)
            break;
 
        if (!isNull1 &&
            DatumGetInt32(FunctionCall2Coll(&scankey->sk_func,
                                            scankey->sk_collation,
                                            datum1,
                                            datum2)) != 0)
            break;
 
        keepnatts++;
    }
 
    /*
     * Assert that _bt_keep_natts_fast() agrees with us in passing.  This is
     * expected in an allequalimage index.
     */
    Assert(!itup_key->allequalimage ||
           keepnatts == _bt_keep_natts_fast(rel, lastleft, firstright));
 
    return keepnatts;
}

References _bt_keep_natts_fast(), BTScanInsertData::allequalimage, Assert, attnum, DatumGetInt32(), fb(), FunctionCall2Coll(), BTScanInsertData::heapkeyspace, index_getattr(), IndexRelationGetNumberOfKeyAttributes, RelationGetDescr, and BTScanInsertData::scankeys.

Referenced by _bt_truncate().

_bt_keep_natts_fast()

int _bt_keep_natts_fast	(	Relation	rel,
		IndexTuple	lastleft,
		IndexTuple	firstright
	)

Definition at line 911 of file nbtutils.c.

{
    TupleDesc   itupdesc = RelationGetDescr(rel);
    int         keysz = IndexRelationGetNumberOfKeyAttributes(rel);
    int         keepnatts;
 
    keepnatts = 1;
    for (int attnum = 1; attnum <= keysz; attnum++)
    {
        Datum       datum1,
                    datum2;
        bool        isNull1,
                    isNull2;
        CompactAttribute *att;
 
        datum1 = index_getattr(lastleft, attnum, itupdesc, &isNull1);
        datum2 = index_getattr(firstright, attnum, itupdesc, &isNull2);
        att = TupleDescCompactAttr(itupdesc, attnum - 1);
 
        if (isNull1 != isNull2)
            break;
 
        if (!isNull1 &&
            !datum_image_eq(datum1, datum2, att->attbyval, att->attlen))
            break;
 
        keepnatts++;
    }
 
    return keepnatts;
}

References CompactAttribute::attbyval, CompactAttribute::attlen, attnum, datum_image_eq(), fb(), index_getattr(), IndexRelationGetNumberOfKeyAttributes, RelationGetDescr, and TupleDescCompactAttr().

Referenced by _bt_afternewitemoff(), _bt_bottomupdel_pass(), _bt_dedup_pass(), _bt_do_singleval(), _bt_keep_natts(), _bt_load(), _bt_set_startikey(), _bt_split_penalty(), and _bt_strategy().

_bt_killitems()

void _bt_killitems

(

IndexScanDesc

scan

)

Definition at line 191 of file nbtutils.c.

{
    Relation    rel = scan->indexRelation;
    BTScanOpaque so = (BTScanOpaque) scan->opaque;
    Page        page;
    BTPageOpaque opaque;
    OffsetNumber minoff;
    OffsetNumber maxoff;
    int         numKilled = so->numKilled;
    bool        killedsomething = false;
    Buffer      buf;
 
    Assert(numKilled > 0);
    Assert(BTScanPosIsValid(so->currPos));
    Assert(scan->heapRelation != NULL); /* can't be a bitmap index scan */
 
    /* Always invalidate so->killedItems[] before leaving so->currPos */
    so->numKilled = 0;
 
    /*
     * We need to iterate through so->killedItems[] in leaf page order; the
     * loop below expects this (when marking posting list tuples, at least).
     * so->killedItems[] is now in whatever order the scan returned items in.
     * Scrollable cursor scans might have even saved the same item/TID twice.
     *
     * Sort and unique-ify so->killedItems[] to deal with all this.
     */
    if (numKilled > 1)
    {
        qsort(so->killedItems, numKilled, sizeof(int), _bt_compare_int);
        numKilled = qunique(so->killedItems, numKilled, sizeof(int),
                            _bt_compare_int);
    }
 
    if (!so->dropPin)
    {
        /*
         * We have held the pin on this page since we read the index tuples,
         * so all we need to do is lock it.  The pin will have prevented
         * concurrent VACUUMs from recycling any of the TIDs on the page.
         */
        Assert(BTScanPosIsPinned(so->currPos));
        buf = so->currPos.buf;
        _bt_lockbuf(rel, buf, BT_READ);
    }
    else
    {
        XLogRecPtr  latestlsn;
 
        Assert(!BTScanPosIsPinned(so->currPos));
        buf = _bt_getbuf(rel, so->currPos.currPage, BT_READ);
 
        latestlsn = BufferGetLSNAtomic(buf);
        Assert(so->currPos.lsn <= latestlsn);
        if (so->currPos.lsn != latestlsn)
        {
            /* Modified, give up on hinting */
            _bt_relbuf(rel, buf);
            return;
        }
 
        /* Unmodified, hinting is safe */
    }
 
    page = BufferGetPage(buf);
    opaque = BTPageGetOpaque(page);
    minoff = P_FIRSTDATAKEY(opaque);
    maxoff = PageGetMaxOffsetNumber(page);
 
    /* Iterate through so->killedItems[] in leaf page order */
    for (int i = 0; i < numKilled; i++)
    {
        int         itemIndex = so->killedItems[i];
        BTScanPosItem *kitem = &so->currPos.items[itemIndex];
        OffsetNumber offnum = kitem->indexOffset;
 
        Assert(itemIndex >= so->currPos.firstItem &&
               itemIndex <= so->currPos.lastItem);
        Assert(i == 0 ||
               offnum >= so->currPos.items[so->killedItems[i - 1]].indexOffset);
 
        if (offnum < minoff)
            continue;           /* pure paranoia */
        while (offnum <= maxoff)
        {
            ItemId      iid = PageGetItemId(page, offnum);
            IndexTuple  ituple = (IndexTuple) PageGetItem(page, iid);
            bool        killtuple = false;
 
            if (BTreeTupleIsPosting(ituple))
            {
                int         pi = i + 1;
                int         nposting = BTreeTupleGetNPosting(ituple);
                int         j;
 
                /*
                 * Note that the page may have been modified in almost any way
                 * since we first read it (in the !so->dropPin case), so it's
                 * possible that this posting list tuple wasn't a posting list
                 * tuple when we first encountered its heap TIDs.
                 */
                for (j = 0; j < nposting; j++)
                {
                    ItemPointer item = BTreeTupleGetPostingN(ituple, j);
 
                    if (!ItemPointerEquals(item, &kitem->heapTid))
                        break;  /* out of posting list loop */
 
                    /*
                     * kitem must have matching offnum when heap TIDs match,
                     * though only in the common case where the page can't
                     * have been concurrently modified
                     */
                    Assert(kitem->indexOffset == offnum || !so->dropPin);
 
                    /*
                     * Read-ahead to later kitems here.
                     *
                     * We rely on the assumption that not advancing kitem here
                     * will prevent us from considering the posting list tuple
                     * fully dead by not matching its next heap TID in next
                     * loop iteration.
                     *
                     * If, on the other hand, this is the final heap TID in
                     * the posting list tuple, then tuple gets killed
                     * regardless (i.e. we handle the case where the last
                     * kitem is also the last heap TID in the last index tuple
                     * correctly -- posting tuple still gets killed).
                     */
                    if (pi < numKilled)
                        kitem = &so->currPos.items[so->killedItems[pi++]];
                }
 
                /*
                 * Don't bother advancing the outermost loop's int iterator to
                 * avoid processing killed items that relate to the same
                 * offnum/posting list tuple.  This micro-optimization hardly
                 * seems worth it.  (Further iterations of the outermost loop
                 * will fail to match on this same posting list's first heap
                 * TID instead, so we'll advance to the next offnum/index
                 * tuple pretty quickly.)
                 */
                if (j == nposting)
                    killtuple = true;
            }
            else if (ItemPointerEquals(&ituple->t_tid, &kitem->heapTid))
                killtuple = true;
 
            /*
             * Mark index item as dead, if it isn't already.  Since this
             * happens while holding a buffer lock possibly in shared mode,
             * it's possible that multiple processes attempt to do this
             * simultaneously, leading to multiple full-page images being sent
             * to WAL (if wal_log_hints or data checksums are enabled), which
             * is undesirable.
             */
            if (killtuple && !ItemIdIsDead(iid))
            {
                if (!killedsomething)
                {
                    /*
                     * Use the hint bit infrastructure to check if we can
                     * update the page while just holding a share lock. If we
                     * are not allowed, there's no point continuing.
                     */
                    if (!BufferBeginSetHintBits(buf))
                        goto unlock_page;
                }
 
                /* found the item/all posting list items */
                ItemIdMarkDead(iid);
                killedsomething = true;
                break;          /* out of inner search loop */
            }
            offnum = OffsetNumberNext(offnum);
        }
    }
 
    /*
     * Since this can be redone later if needed, mark as dirty hint.
     *
     * Whenever we mark anything LP_DEAD, we also set the page's
     * BTP_HAS_GARBAGE flag, which is likewise just a hint.  (Note that we
     * only rely on the page-level flag in !heapkeyspace indexes.)
     */
    if (killedsomething)
    {
        opaque->btpo_flags |= BTP_HAS_GARBAGE;
        BufferFinishSetHintBits(buf, true, true);
    }
 
unlock_page:
    if (!so->dropPin)
        _bt_unlockbuf(rel, buf);
    else
        _bt_relbuf(rel, buf);
}

References _bt_compare_int(), _bt_getbuf(), _bt_lockbuf(), _bt_relbuf(), _bt_unlockbuf(), Assert, BT_READ, BTP_HAS_GARBAGE, BTPageGetOpaque, BTPageOpaqueData::btpo_flags, BTreeTupleGetNPosting(), BTreeTupleGetPostingN(), BTreeTupleIsPosting(), BTScanPosIsPinned, BTScanPosIsValid, buf, BufferBeginSetHintBits(), BufferFinishSetHintBits(), BufferGetLSNAtomic(), BufferGetPage(), fb(), IndexScanDescData::heapRelation, i, BTScanPosItem::indexOffset, IndexScanDescData::indexRelation, ItemIdIsDead, ItemIdMarkDead, ItemPointerEquals(), j, OffsetNumberNext, IndexScanDescData::opaque, P_FIRSTDATAKEY, PageGetItem(), PageGetItemId(), PageGetMaxOffsetNumber(), qsort, and qunique().

Referenced by _bt_steppage(), btendscan(), btrescan(), and btrestrpos().

_bt_mkscankey()

BTScanInsert _bt_mkscankey	(	Relation	rel,
		IndexTuple	itup
	)

Definition at line 61 of file nbtutils.c.

{
    BTScanInsert key;
    ScanKey     skey;
    TupleDesc   itupdesc;
    int         indnkeyatts;
    int16      *indoption;
    int         tupnatts;
    int         i;
 
    itupdesc = RelationGetDescr(rel);
    indnkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    indoption = rel->rd_indoption;
    tupnatts = itup ? BTreeTupleGetNAtts(itup, rel) : 0;
 
    Assert(tupnatts <= IndexRelationGetNumberOfAttributes(rel));
 
    /*
     * We'll execute search using scan key constructed on key columns.
     * Truncated attributes and non-key attributes are omitted from the final
     * scan key.
     */
    key = palloc(offsetof(BTScanInsertData, scankeys) +
                 sizeof(ScanKeyData) * indnkeyatts);
    if (itup)
        _bt_metaversion(rel, &key->heapkeyspace, &key->allequalimage);
    else
    {
        /* Utility statement callers can set these fields themselves */
        key->heapkeyspace = true;
        key->allequalimage = false;
    }
    key->anynullkeys = false;   /* initial assumption */
    key->nextkey = false;       /* usual case, required by btinsert */
    key->backward = false;      /* usual case, required by btinsert */
    key->keysz = Min(indnkeyatts, tupnatts);
    key->scantid = key->heapkeyspace && itup ?
        BTreeTupleGetHeapTID(itup) : NULL;
    skey = key->scankeys;
    for (i = 0; i < indnkeyatts; i++)
    {
        FmgrInfo   *procinfo;
        Datum       arg;
        bool        null;
        int         flags;
 
        /*
         * We can use the cached (default) support procs since no cross-type
         * comparison can be needed.
         */
        procinfo = index_getprocinfo(rel, i + 1, BTORDER_PROC);
 
        /*
         * Key arguments built from truncated attributes (or when caller
         * provides no tuple) are defensively represented as NULL values. They
         * should never be used.
         */
        if (i < tupnatts)
            arg = index_getattr(itup, i + 1, itupdesc, &null);
        else
        {
            arg = (Datum) 0;
            null = true;
        }
        flags = (null ? SK_ISNULL : 0) | (indoption[i] << SK_BT_INDOPTION_SHIFT);
        ScanKeyEntryInitializeWithInfo(&skey[i],
                                       flags,
                                       (AttrNumber) (i + 1),
                                       InvalidStrategy,
                                       InvalidOid,
                                       rel->rd_indcollation[i],
                                       procinfo,
                                       arg);
        /* Record if any key attribute is NULL (or truncated) */
        if (null)
            key->anynullkeys = true;
    }
 
    /*
     * In NULLS NOT DISTINCT mode, we pretend that there are no null keys, so
     * that full uniqueness check is done.
     */
    if (rel->rd_index->indnullsnotdistinct)
        key->anynullkeys = false;
 
    return key;
}

References _bt_metaversion(), arg, Assert, BTORDER_PROC, BTreeTupleGetHeapTID(), BTreeTupleGetNAtts, fb(), i, index_getattr(), index_getprocinfo(), IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, InvalidOid, InvalidStrategy, Min, palloc(), RelationData::rd_indcollation, RelationData::rd_index, RelationData::rd_indoption, RelationGetDescr, ScanKeyEntryInitializeWithInfo(), SK_BT_INDOPTION_SHIFT, and SK_ISNULL.

Referenced by _bt_doinsert(), _bt_leafbuild(), _bt_pagedel(), bt_mkscankey_pivotsearch(), bt_rootdescend(), tuplesort_begin_cluster(), and tuplesort_begin_index_btree().

_bt_start_vacuum()

BTCycleId _bt_start_vacuum

(

Relation

rel

)

Definition at line 473 of file nbtutils.c.

{
    BTCycleId   result;
    int         i;
    BTOneVacInfo *vac;
 
    LWLockAcquire(BtreeVacuumLock, LW_EXCLUSIVE);
 
    /*
     * Assign the next cycle ID, being careful to avoid zero as well as the
     * reserved high values.
     */
    result = ++(btvacinfo->cycle_ctr);
    if (result == 0 || result > MAX_BT_CYCLE_ID)
        result = btvacinfo->cycle_ctr = 1;
 
    /* Let's just make sure there's no entry already for this index */
    for (i = 0; i < btvacinfo->num_vacuums; i++)
    {
        vac = &btvacinfo->vacuums[i];
        if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
            vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId)
        {
            /*
             * Unlike most places in the backend, we have to explicitly
             * release our LWLock before throwing an error.  This is because
             * we expect _bt_end_vacuum() to be called before transaction
             * abort cleanup can run to release LWLocks.
             */
            LWLockRelease(BtreeVacuumLock);
            elog(ERROR, "multiple active vacuums for index \"%s\"",
                 RelationGetRelationName(rel));
        }
    }
 
    /* OK, add an entry */
    if (btvacinfo->num_vacuums >= btvacinfo->max_vacuums)
    {
        LWLockRelease(BtreeVacuumLock);
        elog(ERROR, "out of btvacinfo slots");
    }
    vac = &btvacinfo->vacuums[btvacinfo->num_vacuums];
    vac->relid = rel->rd_lockInfo.lockRelId;
    vac->cycleid = result;
    btvacinfo->num_vacuums++;
 
    LWLockRelease(BtreeVacuumLock);
    return result;
}

References btvacinfo, BTVacInfo::cycle_ctr, BTOneVacInfo::cycleid, LockRelId::dbId, elog, ERROR, fb(), i, LockInfoData::lockRelId, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAX_BT_CYCLE_ID, BTVacInfo::max_vacuums, BTVacInfo::num_vacuums, RelationData::rd_lockInfo, RelationGetRelationName, BTOneVacInfo::relid, LockRelId::relId, result, and BTVacInfo::vacuums.

Referenced by btbulkdelete().

_bt_truncate()

IndexTuple _bt_truncate	(	Relation	rel,
		IndexTuple	lastleft,
		IndexTuple	firstright,
		BTScanInsert	itup_key
	)

Definition at line 692 of file nbtutils.c.

{
    TupleDesc   itupdesc = RelationGetDescr(rel);
    int16       nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
    int         keepnatts;
    IndexTuple  pivot;
    IndexTuple  tidpivot;
    ItemPointer pivotheaptid;
    Size        newsize;
 
    /*
     * We should only ever truncate non-pivot tuples from leaf pages.  It's
     * never okay to truncate when splitting an internal page.
     */
    Assert(!BTreeTupleIsPivot(lastleft) && !BTreeTupleIsPivot(firstright));
 
    /* Determine how many attributes must be kept in truncated tuple */
    keepnatts = _bt_keep_natts(rel, lastleft, firstright, itup_key);
 
#ifdef DEBUG_NO_TRUNCATE
    /* Force truncation to be ineffective for testing purposes */
    keepnatts = nkeyatts + 1;
#endif
 
    pivot = index_truncate_tuple(itupdesc, firstright,
                                 Min(keepnatts, nkeyatts));
 
    if (BTreeTupleIsPosting(pivot))
    {
        /*
         * index_truncate_tuple() just returns a straight copy of firstright
         * when it has no attributes to truncate.  When that happens, we may
         * need to truncate away a posting list here instead.
         */
        Assert(keepnatts == nkeyatts || keepnatts == nkeyatts + 1);
        Assert(IndexRelationGetNumberOfAttributes(rel) == nkeyatts);
        pivot->t_info &= ~INDEX_SIZE_MASK;
        pivot->t_info |= MAXALIGN(BTreeTupleGetPostingOffset(firstright));
    }
 
    /*
     * If there is a distinguishing key attribute within pivot tuple, we're
     * done
     */
    if (keepnatts <= nkeyatts)
    {
        BTreeTupleSetNAtts(pivot, keepnatts, false);
        return pivot;
    }
 
    /*
     * We have to store a heap TID in the new pivot tuple, since no non-TID
     * key attribute value in firstright distinguishes the right side of the
     * split from the left side.  nbtree conceptualizes this case as an
     * inability to truncate away any key attributes, since heap TID is
     * treated as just another key attribute (despite lacking a pg_attribute
     * entry).
     *
     * Use enlarged space that holds a copy of pivot.  We need the extra space
     * to store a heap TID at the end (using the special pivot tuple
     * representation).  Note that the original pivot already has firstright's
     * possible posting list/non-key attribute values removed at this point.
     */
    newsize = MAXALIGN(IndexTupleSize(pivot)) + MAXALIGN(sizeof(ItemPointerData));
    tidpivot = palloc0(newsize);
    memcpy(tidpivot, pivot, MAXALIGN(IndexTupleSize(pivot)));
    /* Cannot leak memory here */
    pfree(pivot);
 
    /*
     * Store all of firstright's key attribute values plus a tiebreaker heap
     * TID value in enlarged pivot tuple
     */
    tidpivot->t_info &= ~INDEX_SIZE_MASK;
    tidpivot->t_info |= newsize;
    BTreeTupleSetNAtts(tidpivot, nkeyatts, true);
    pivotheaptid = BTreeTupleGetHeapTID(tidpivot);
 
    /*
     * Lehman & Yao use lastleft as the leaf high key in all cases, but don't
     * consider suffix truncation.  It seems like a good idea to follow that
     * example in cases where no truncation takes place -- use lastleft's heap
     * TID.  (This is also the closest value to negative infinity that's
     * legally usable.)
     */
    ItemPointerCopy(BTreeTupleGetMaxHeapTID(lastleft), pivotheaptid);
 
    /*
     * We're done.  Assert() that heap TID invariants hold before returning.
     *
     * Lehman and Yao require that the downlink to the right page, which is to
     * be inserted into the parent page in the second phase of a page split be
     * a strict lower bound on items on the right page, and a non-strict upper
     * bound for items on the left page.  Assert that heap TIDs follow these
     * invariants, since a heap TID value is apparently needed as a
     * tiebreaker.
     */
#ifndef DEBUG_NO_TRUNCATE
    Assert(ItemPointerCompare(BTreeTupleGetMaxHeapTID(lastleft),
                              BTreeTupleGetHeapTID(firstright)) < 0);
    Assert(ItemPointerCompare(pivotheaptid,
                              BTreeTupleGetHeapTID(lastleft)) >= 0);
    Assert(ItemPointerCompare(pivotheaptid,
                              BTreeTupleGetHeapTID(firstright)) < 0);
#else
 
    /*
     * Those invariants aren't guaranteed to hold for lastleft + firstright
     * heap TID attribute values when they're considered here only because
     * DEBUG_NO_TRUNCATE is defined (a heap TID is probably not actually
     * needed as a tiebreaker).  DEBUG_NO_TRUNCATE must therefore use a heap
     * TID value that always works as a strict lower bound for items to the
     * right.  In particular, it must avoid using firstright's leading key
     * attribute values along with lastleft's heap TID value when lastleft's
     * TID happens to be greater than firstright's TID.
     */
    ItemPointerCopy(BTreeTupleGetHeapTID(firstright), pivotheaptid);
 
    /*
     * Pivot heap TID should never be fully equal to firstright.  Note that
     * the pivot heap TID will still end up equal to lastleft's heap TID when
     * that's the only usable value.
     */
    ItemPointerSetOffsetNumber(pivotheaptid,
                               OffsetNumberPrev(ItemPointerGetOffsetNumber(pivotheaptid)));
    Assert(ItemPointerCompare(pivotheaptid,
                              BTreeTupleGetHeapTID(firstright)) < 0);
#endif
 
    return tidpivot;
}

References _bt_keep_natts(), Assert, BTreeTupleGetHeapTID(), BTreeTupleGetMaxHeapTID(), BTreeTupleGetPostingOffset(), BTreeTupleIsPivot(), BTreeTupleIsPosting(), BTreeTupleSetNAtts(), fb(), index_truncate_tuple(), IndexRelationGetNumberOfAttributes, IndexRelationGetNumberOfKeyAttributes, IndexTupleSize(), ItemPointerCompare(), ItemPointerCopy(), ItemPointerGetOffsetNumber(), ItemPointerSetOffsetNumber(), MAXALIGN, memcpy(), Min, OffsetNumberPrev, palloc0(), pfree(), and RelationGetDescr.

Referenced by _bt_buildadd(), and _bt_split().

_bt_vacuum_cycleid()

BTCycleId _bt_vacuum_cycleid

(

Relation

rel

)

Definition at line 439 of file nbtutils.c.

{
    BTCycleId   result = 0;
    int         i;
 
    /* Share lock is enough since this is a read-only operation */
    LWLockAcquire(BtreeVacuumLock, LW_SHARED);
 
    for (i = 0; i < btvacinfo->num_vacuums; i++)
    {
        BTOneVacInfo *vac = &btvacinfo->vacuums[i];
 
        if (vac->relid.relId == rel->rd_lockInfo.lockRelId.relId &&
            vac->relid.dbId == rel->rd_lockInfo.lockRelId.dbId)
        {
            result = vac->cycleid;
            break;
        }
    }
 
    LWLockRelease(BtreeVacuumLock);
    return result;
}

References btvacinfo, BTOneVacInfo::cycleid, LockRelId::dbId, fb(), i, LockInfoData::lockRelId, LW_SHARED, LWLockAcquire(), LWLockRelease(), BTVacInfo::num_vacuums, RelationData::rd_lockInfo, BTOneVacInfo::relid, LockRelId::relId, result, and BTVacInfo::vacuums.

Referenced by _bt_split().

btbuildphasename()

char * btbuildphasename

(

int64

phasenum

)

Definition at line 644 of file nbtutils.c.

{
    switch (phasenum)
    {
        case PROGRESS_CREATEIDX_SUBPHASE_INITIALIZE:
            return "initializing";
        case PROGRESS_BTREE_PHASE_INDEXBUILD_TABLESCAN:
            return "scanning table";
        case PROGRESS_BTREE_PHASE_PERFORMSORT_1:
            return "sorting live tuples";
        case PROGRESS_BTREE_PHASE_PERFORMSORT_2:
            return "sorting dead tuples";
        case PROGRESS_BTREE_PHASE_LEAF_LOAD:
            return "loading tuples in tree";
        default:
            return NULL;
    }
}

References fb(), PROGRESS_BTREE_PHASE_INDEXBUILD_TABLESCAN, PROGRESS_BTREE_PHASE_LEAF_LOAD, PROGRESS_BTREE_PHASE_PERFORMSORT_1, PROGRESS_BTREE_PHASE_PERFORMSORT_2, and PROGRESS_CREATEIDX_SUBPHASE_INITIALIZE.

Referenced by bthandler().

btoptions()

bytea * btoptions	(	Datum	reloptions,
		bool	validate
	)

Definition at line 598 of file nbtutils.c.

{
    static const relopt_parse_elt tab[] = {
        {"fillfactor", RELOPT_TYPE_INT, offsetof(BTOptions, fillfactor)},
        {"vacuum_cleanup_index_scale_factor", RELOPT_TYPE_REAL,
        offsetof(BTOptions, vacuum_cleanup_index_scale_factor)},
        {"deduplicate_items", RELOPT_TYPE_BOOL,
        offsetof(BTOptions, deduplicate_items)}
    };
 
    return (bytea *) build_reloptions(reloptions, validate,
                                      RELOPT_KIND_BTREE,
                                      sizeof(BTOptions),
                                      tab, lengthof(tab));
}

References build_reloptions(), fb(), fillfactor, lengthof, RELOPT_KIND_BTREE, RELOPT_TYPE_BOOL, RELOPT_TYPE_INT, RELOPT_TYPE_REAL, and validate().

Referenced by bthandler().

btproperty()

bool btproperty	(	Oid	index_oid,
		int	attno,
		IndexAMProperty	prop,
		const char *	propname,
		bool *	res,
		bool *	isnull
	)

Definition at line 621 of file nbtutils.c.

{
    switch (prop)
    {
        case AMPROP_RETURNABLE:
            /* answer only for columns, not AM or whole index */
            if (attno == 0)
                return false;
            /* otherwise, btree can always return data */
            *res = true;
            return true;
 
        default:
            return false;       /* punt to generic code */
    }
}

References AMPROP_RETURNABLE.

Referenced by bthandler().

BTreeShmemInit()

static void BTreeShmemInit ( void *  arg )

static

Definition at line 584 of file nbtutils.c.

{
    /*
     * It doesn't really matter what the cycle counter starts at, but having
     * it always start the same doesn't seem good.  Seed with low-order bits
     * of time() instead.
     */
    btvacinfo->cycle_ctr = (BTCycleId) time(NULL);
 
    btvacinfo->num_vacuums = 0;
    btvacinfo->max_vacuums = MaxBackends;
}

References btvacinfo, BTVacInfo::cycle_ctr, fb(), BTVacInfo::max_vacuums, MaxBackends, and BTVacInfo::num_vacuums.

BTreeShmemRequest()

static void BTreeShmemRequest ( void *  arg )

static

Definition at line 567 of file nbtutils.c.

{
    Size        size;
 
    size = offsetof(BTVacInfo, vacuums);
    size = add_size(size, mul_size(MaxBackends, sizeof(BTOneVacInfo)));
 
    ShmemRequestStruct(.name = "BTree Vacuum State",
                       .size = size,
                       .ptr = (void **) &btvacinfo,
        );
}

References add_size(), btvacinfo, fb(), MaxBackends, mul_size(), name, and ShmemRequestStruct.

Variable Documentation

BTreeShmemCallbacks

const ShmemCallbacks BTreeShmemCallbacks

Initial value:

= {
    .request_fn = BTreeShmemRequest,
    .init_fn = BTreeShmemInit,
}

Definition at line 424 of file nbtutils.c.

                                           {
    .request_fn = BTreeShmemRequest,
    .init_fn = BTreeShmemInit,
};

btvacinfo

BTVacInfo* btvacinfo

static

Definition at line 419 of file nbtutils.c.

Referenced by _bt_end_vacuum(), _bt_start_vacuum(), _bt_vacuum_cycleid(), BTreeShmemInit(), and BTreeShmemRequest().