pg_publication.c

Go to the documentation of this file.

/*-------------------------------------------------------------------------
 *
 * pg_publication.c
 *      publication C API manipulation
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *      src/backend/catalog/pg_publication.c
 *
 *-------------------------------------------------------------------------
 */
 
#include "postgres.h"
 
#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/tableam.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/objectaddress.h"
#include "catalog/partition.h"
#include "catalog/pg_inherits.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_publication.h"
#include "catalog/pg_publication_namespace.h"
#include "catalog/pg_publication_rel.h"
#include "catalog/pg_type.h"
#include "commands/publicationcmds.h"
#include "funcapi.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
 
/* Records association between publication and published table */
typedef struct
{
    Oid         relid;          /* OID of published table */
    Oid         pubid;          /* OID of publication that publishes this
                                 * table. */
} published_rel;
 
/*
 * Check if relation can be in given publication and throws appropriate
 * error if not.
 */
static void
check_publication_add_relation(PublicationRelInfo *pri)
{
    Relation    targetrel = pri->relation;
    const char *errormsg;
 
    if (pri->except)
        errormsg = gettext_noop("cannot use publication EXCEPT clause for relation \"%s\"");
    else
        errormsg = gettext_noop("cannot add relation \"%s\" to publication");
 
    /* If in EXCEPT clause, must be root partitioned table */
    if (pri->except && targetrel->rd_rel->relispartition)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg(errormsg, RelationGetRelationName(targetrel)),
                 errdetail("This operation is not supported for individual partitions.")));
 
    /* Must be a regular or partitioned table */
    if (RelationGetForm(targetrel)->relkind != RELKIND_RELATION &&
        RelationGetForm(targetrel)->relkind != RELKIND_PARTITIONED_TABLE)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg(errormsg, RelationGetRelationName(targetrel)),
                 errdetail_relkind_not_supported(RelationGetForm(targetrel)->relkind)));
 
    /* Can't be system table */
    if (IsCatalogRelation(targetrel))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg(errormsg, RelationGetRelationName(targetrel)),
                 errdetail("This operation is not supported for system tables.")));
 
    /* UNLOGGED and TEMP relations cannot be part of publication. */
    if (targetrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg(errormsg, RelationGetRelationName(targetrel)),
                 errdetail("This operation is not supported for temporary tables.")));
    else if (targetrel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg(errormsg, RelationGetRelationName(targetrel)),
                 errdetail("This operation is not supported for unlogged tables.")));
}
 
/*
 * Check if schema can be in given publication and throw appropriate error if
 * not.
 */
static void
check_publication_add_schema(Oid schemaid)
{
    /* Can't be system namespace */
    if (IsCatalogNamespace(schemaid) || IsToastNamespace(schemaid))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("cannot add schema \"%s\" to publication",
                        get_namespace_name(schemaid)),
                 errdetail("This operation is not supported for system schemas.")));
 
    /* Can't be temporary namespace */
    if (isAnyTempNamespace(schemaid))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("cannot add schema \"%s\" to publication",
                        get_namespace_name(schemaid)),
                 errdetail("Temporary schemas cannot be replicated.")));
}
 
/*
 * Returns if relation represented by oid and Form_pg_class entry
 * is publishable.
 *
 * Does same checks as check_publication_add_relation() above except for
 * RELKIND_SEQUENCE, but does not need relation to be opened and also does
 * not throw errors. Here, the additional check is to support ALL SEQUENCES
 * publication.
 *
 * XXX  This also excludes all tables with relid < FirstNormalObjectId,
 * ie all tables created during initdb.  This mainly affects the preinstalled
 * information_schema.  IsCatalogRelationOid() only excludes tables with
 * relid < FirstUnpinnedObjectId, making that test rather redundant,
 * but really we should get rid of the FirstNormalObjectId test not
 * IsCatalogRelationOid.  We can't do so today because we don't want
 * information_schema tables to be considered publishable; but this test
 * is really inadequate for that, since the information_schema could be
 * dropped and reloaded and then it'll be considered publishable.  The best
 * long-term solution may be to add a "relispublishable" bool to pg_class,
 * and depend on that instead of OID checks.
 */
static bool
is_publishable_class(Oid relid, Form_pg_class reltuple)
{
    return (reltuple->relkind == RELKIND_RELATION ||
            reltuple->relkind == RELKIND_PARTITIONED_TABLE ||
            reltuple->relkind == RELKIND_SEQUENCE) &&
        !IsCatalogRelationOid(relid) &&
        reltuple->relpersistence == RELPERSISTENCE_PERMANENT &&
        relid >= FirstNormalObjectId;
}
 
/*
 * Another variant of is_publishable_class(), taking a Relation.
 */
bool
is_publishable_relation(Relation rel)
{
    return is_publishable_class(RelationGetRelid(rel), rel->rd_rel);
}
 
/*
 * SQL-callable variant of the above
 *
 * This returns null when the relation does not exist.  This is intended to be
 * used for example in psql to avoid gratuitous errors when there are
 * concurrent catalog changes.
 */
Datum
pg_relation_is_publishable(PG_FUNCTION_ARGS)
{
    Oid         relid = PG_GETARG_OID(0);
    HeapTuple   tuple;
    bool        result;
 
    tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
    if (!HeapTupleIsValid(tuple))
        PG_RETURN_NULL();
    result = is_publishable_class(relid, (Form_pg_class) GETSTRUCT(tuple));
    ReleaseSysCache(tuple);
    PG_RETURN_BOOL(result);
}
 
/*
 * Returns true if the ancestor is in the list of published relations.
 * Otherwise, returns false.
 */
static bool
is_ancestor_member_tableinfos(Oid ancestor, List *table_infos)
{
    ListCell   *lc;
 
    foreach(lc, table_infos)
    {
        Oid         relid = ((published_rel *) lfirst(lc))->relid;
 
        if (relid == ancestor)
            return true;
    }
 
    return false;
}
 
/*
 * Filter out the partitions whose parent tables are also present in the list.
 */
static void
filter_partitions(List *table_infos)
{
    ListCell   *lc;
 
    foreach(lc, table_infos)
    {
        bool        skip = false;
        List       *ancestors = NIL;
        ListCell   *lc2;
        published_rel *table_info = (published_rel *) lfirst(lc);
 
        if (get_rel_relispartition(table_info->relid))
            ancestors = get_partition_ancestors(table_info->relid);
 
        foreach(lc2, ancestors)
        {
            Oid         ancestor = lfirst_oid(lc2);
 
            if (is_ancestor_member_tableinfos(ancestor, table_infos))
            {
                skip = true;
                break;
            }
        }
 
        if (skip)
            table_infos = foreach_delete_current(table_infos, lc);
    }
}
 
/*
 * Returns true if any schema is associated with the publication, false if no
 * schema is associated with the publication.
 */
bool
is_schema_publication(Oid pubid)
{
    Relation    pubschsrel;
    ScanKeyData scankey;
    SysScanDesc scan;
    HeapTuple   tup;
    bool        result = false;
 
    pubschsrel = table_open(PublicationNamespaceRelationId, AccessShareLock);
    ScanKeyInit(&scankey,
                Anum_pg_publication_namespace_pnpubid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(pubid));
 
    scan = systable_beginscan(pubschsrel,
                              PublicationNamespacePnnspidPnpubidIndexId,
                              true, NULL, 1, &scankey);
    tup = systable_getnext(scan);
    result = HeapTupleIsValid(tup);
 
    systable_endscan(scan);
    table_close(pubschsrel, AccessShareLock);
 
    return result;
}
 
/*
 * Returns true if the publication has explicitly included relation (i.e.,
 * not marked as EXCEPT).
 */
bool
is_table_publication(Oid pubid)
{
    Relation    pubrelsrel;
    ScanKeyData scankey;
    SysScanDesc scan;
    HeapTuple   tup;
    bool        result = false;
 
    pubrelsrel = table_open(PublicationRelRelationId, AccessShareLock);
    ScanKeyInit(&scankey,
                Anum_pg_publication_rel_prpubid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(pubid));
 
    scan = systable_beginscan(pubrelsrel,
                              PublicationRelPrpubidIndexId,
                              true, NULL, 1, &scankey);
    tup = systable_getnext(scan);
    if (HeapTupleIsValid(tup))
    {
        Form_pg_publication_rel pubrel;
 
        pubrel = (Form_pg_publication_rel) GETSTRUCT(tup);
 
        /*
         * For any publication, pg_publication_rel contains either only EXCEPT
         * entries or only explicitly included tables. Therefore, examining
         * the first tuple is sufficient to determine table inclusion.
         */
        result = !pubrel->prexcept;
    }
 
    systable_endscan(scan);
    table_close(pubrelsrel, AccessShareLock);
 
    return result;
}
 
/*
 * Returns true if the relation has column list associated with the
 * publication, false otherwise.
 *
 * If a column list is found, the corresponding bitmap is returned through the
 * cols parameter, if provided. The bitmap is constructed within the given
 * memory context (mcxt).
 */
bool
check_and_fetch_column_list(Publication *pub, Oid relid, MemoryContext mcxt,
                            Bitmapset **cols)
{
    HeapTuple   cftuple;
    bool        found = false;
 
    if (pub->alltables)
        return false;
 
    cftuple = SearchSysCache2(PUBLICATIONRELMAP,
                              ObjectIdGetDatum(relid),
                              ObjectIdGetDatum(pub->oid));
    if (HeapTupleIsValid(cftuple))
    {
        Datum       cfdatum;
        bool        isnull;
 
        /* Lookup the column list attribute. */
        cfdatum = SysCacheGetAttr(PUBLICATIONRELMAP, cftuple,
                                  Anum_pg_publication_rel_prattrs, &isnull);
 
        /* Was a column list found? */
        if (!isnull)
        {
            /* Build the column list bitmap in the given memory context. */
            if (cols)
                *cols = pub_collist_to_bitmapset(*cols, cfdatum, mcxt);
 
            found = true;
        }
 
        ReleaseSysCache(cftuple);
    }
 
    return found;
}
 
/*
 * Gets the relations based on the publication partition option for a specified
 * relation.
 */
List *
GetPubPartitionOptionRelations(List *result, PublicationPartOpt pub_partopt,
                               Oid relid)
{
    if (get_rel_relkind(relid) == RELKIND_PARTITIONED_TABLE &&
        pub_partopt != PUBLICATION_PART_ROOT)
    {
        List       *all_parts = find_all_inheritors(relid, NoLock,
                                                    NULL);
 
        if (pub_partopt == PUBLICATION_PART_ALL)
            result = list_concat(result, all_parts);
        else if (pub_partopt == PUBLICATION_PART_LEAF)
        {
            ListCell   *lc;
 
            foreach(lc, all_parts)
            {
                Oid         partOid = lfirst_oid(lc);
 
                if (get_rel_relkind(partOid) != RELKIND_PARTITIONED_TABLE)
                    result = lappend_oid(result, partOid);
            }
        }
        else
            Assert(false);
    }
    else
        result = lappend_oid(result, relid);
 
    return result;
}
 
/*
 * Returns the relid of the topmost ancestor that is published via this
 * publication if any and set its ancestor level to ancestor_level,
 * otherwise returns InvalidOid.
 *
 * The ancestor_level value allows us to compare the results for multiple
 * publications, and decide which value is higher up.
 *
 * Note that the list of ancestors should be ordered such that the topmost
 * ancestor is at the end of the list.
 */
Oid
GetTopMostAncestorInPublication(Oid puboid, List *ancestors, int *ancestor_level)
{
    ListCell   *lc;
    Oid         topmost_relid = InvalidOid;
    int         level = 0;
 
    /*
     * Find the "topmost" ancestor that is in this publication.
     */
    foreach(lc, ancestors)
    {
        Oid         ancestor = lfirst_oid(lc);
        List       *apubids = GetRelationIncludedPublications(ancestor);
        List       *aschemaPubids = NIL;
 
        level++;
 
        if (list_member_oid(apubids, puboid))
        {
            topmost_relid = ancestor;
 
            if (ancestor_level)
                *ancestor_level = level;
        }
        else
        {
            aschemaPubids = GetSchemaPublications(get_rel_namespace(ancestor));
            if (list_member_oid(aschemaPubids, puboid))
            {
                topmost_relid = ancestor;
 
                if (ancestor_level)
                    *ancestor_level = level;
            }
        }
 
        list_free(apubids);
        list_free(aschemaPubids);
    }
 
    return topmost_relid;
}
 
/*
 * attnumstoint2vector
 *      Convert a Bitmapset of AttrNumbers into an int2vector.
 *
 * AttrNumber numbers are 0-based, i.e., not offset by
 * FirstLowInvalidHeapAttributeNumber.
 */
static int2vector *
attnumstoint2vector(Bitmapset *attrs)
{
    int2vector *result;
    int         n = bms_num_members(attrs);
    int         i = -1;
    int         j = 0;
 
    result = buildint2vector(NULL, n);
 
    while ((i = bms_next_member(attrs, i)) >= 0)
    {
        Assert(i <= PG_INT16_MAX);
 
        result->values[j++] = (int16) i;
    }
 
    return result;
}
 
/*
 * Insert new publication / relation mapping.
 */
ObjectAddress
publication_add_relation(Oid pubid, PublicationRelInfo *pri,
                         bool if_not_exists, AlterPublicationStmt *alter_stmt)
{
    Relation    rel;
    HeapTuple   tup;
    Datum       values[Natts_pg_publication_rel];
    bool        nulls[Natts_pg_publication_rel];
    Relation    targetrel = pri->relation;
    Oid         relid = RelationGetRelid(targetrel);
    Oid         pubreloid;
    Bitmapset  *attnums;
    Publication *pub = GetPublication(pubid);
    ObjectAddress myself,
                referenced;
    List       *relids = NIL;
    int         i;
    bool        inval_except_table;
 
    rel = table_open(PublicationRelRelationId, RowExclusiveLock);
 
    /*
     * Check for duplicates. Note that this does not really prevent
     * duplicates, it's here just to provide nicer error message in common
     * case. The real protection is the unique key on the catalog.
     */
    if (SearchSysCacheExists2(PUBLICATIONRELMAP, ObjectIdGetDatum(relid),
                              ObjectIdGetDatum(pubid)))
    {
        table_close(rel, RowExclusiveLock);
 
        if (if_not_exists)
            return InvalidObjectAddress;
 
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("relation \"%s\" is already member of publication \"%s\"",
                        RelationGetRelationName(targetrel), pub->name)));
    }
 
    check_publication_add_relation(pri);
 
    /* Validate and translate column names into a Bitmapset of attnums. */
    attnums = pub_collist_validate(pri->relation, pri->columns);
 
    /* Form a tuple. */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));
 
    pubreloid = GetNewOidWithIndex(rel, PublicationRelObjectIndexId,
                                   Anum_pg_publication_rel_oid);
    values[Anum_pg_publication_rel_oid - 1] = ObjectIdGetDatum(pubreloid);
    values[Anum_pg_publication_rel_prpubid - 1] =
        ObjectIdGetDatum(pubid);
    values[Anum_pg_publication_rel_prrelid - 1] =
        ObjectIdGetDatum(relid);
    values[Anum_pg_publication_rel_prexcept - 1] =
        BoolGetDatum(pri->except);
 
    /* Add qualifications, if available */
    if (pri->whereClause != NULL)
        values[Anum_pg_publication_rel_prqual - 1] = CStringGetTextDatum(nodeToString(pri->whereClause));
    else
        nulls[Anum_pg_publication_rel_prqual - 1] = true;
 
    /* Add column list, if available */
    if (pri->columns)
        values[Anum_pg_publication_rel_prattrs - 1] = PointerGetDatum(attnumstoint2vector(attnums));
    else
        nulls[Anum_pg_publication_rel_prattrs - 1] = true;
 
    tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
 
    /* Insert tuple into catalog. */
    CatalogTupleInsert(rel, tup);
    heap_freetuple(tup);
 
    /* Register dependencies as needed */
    ObjectAddressSet(myself, PublicationRelRelationId, pubreloid);
 
    /* Add dependency on the publication */
    ObjectAddressSet(referenced, PublicationRelationId, pubid);
    recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
 
    /* Add dependency on the relation */
    ObjectAddressSet(referenced, RelationRelationId, relid);
    recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
 
    /* Add dependency on the objects mentioned in the qualifications */
    if (pri->whereClause)
        recordDependencyOnSingleRelExpr(&myself, pri->whereClause, relid,
                                        DEPENDENCY_NORMAL, DEPENDENCY_NORMAL,
                                        false);
 
    /* Add dependency on the columns, if any are listed */
    i = -1;
    while ((i = bms_next_member(attnums, i)) >= 0)
    {
        ObjectAddressSubSet(referenced, RelationRelationId, relid, i);
        recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
    }
 
    /* Close the table. */
    table_close(rel, RowExclusiveLock);
 
    /*
     * Determine whether EXCEPT tables require explicit relcache invalidation.
     *
     * For CREATE PUBLICATION with EXCEPT tables, invalidation is skipped
     * here, as CreatePublication() function invalidates all relations as part
     * of defining a FOR ALL TABLES publication.
     *
     * For ALTER PUBLICATION, invalidation is needed only when adding an
     * EXCEPT table to a publication already marked as ALL TABLES. For
     * publications that were originally empty or defined as ALL SEQUENCES and
     * are being converted to ALL TABLES, invalidation is skipped here, as
     * AlterPublicationAllFlags() function invalidates all relations while
     * marking the publication as ALL TABLES publication.
     */
    inval_except_table = (alter_stmt != NULL) && pub->alltables &&
        (alter_stmt->for_all_tables && pri->except);
 
    if (!pri->except || inval_except_table)
    {
        /*
         * Invalidate relcache so that publication info is rebuilt.
         *
         * For the partitioned tables, we must invalidate all partitions
         * contained in the respective partition hierarchies, not just the one
         * explicitly mentioned in the publication. This is required because
         * we implicitly publish the child tables when the parent table is
         * published.
         */
        relids = GetPubPartitionOptionRelations(relids, PUBLICATION_PART_ALL,
                                                relid);
 
        InvalidatePublicationRels(relids);
    }
 
    return myself;
}
 
/*
 * pub_collist_validate
 *      Process and validate the 'columns' list and ensure the columns are all
 *      valid to use for a publication.  Checks for and raises an ERROR for
 *      any unknown columns, system columns, duplicate columns, or virtual
 *      generated columns.
 *
 * Looks up each column's attnum and returns a 0-based Bitmapset of the
 * corresponding attnums.
 */
Bitmapset *
pub_collist_validate(Relation targetrel, List *columns)
{
    Bitmapset  *set = NULL;
    ListCell   *lc;
    TupleDesc   tupdesc = RelationGetDescr(targetrel);
 
    foreach(lc, columns)
    {
        char       *colname = strVal(lfirst(lc));
        AttrNumber  attnum = get_attnum(RelationGetRelid(targetrel), colname);
 
        if (attnum == InvalidAttrNumber)
            ereport(ERROR,
                    errcode(ERRCODE_UNDEFINED_COLUMN),
                    errmsg("column \"%s\" of relation \"%s\" does not exist",
                           colname, RelationGetRelationName(targetrel)));
 
        if (!AttrNumberIsForUserDefinedAttr(attnum))
            ereport(ERROR,
                    errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                    errmsg("cannot use system column \"%s\" in publication column list",
                           colname));
 
        if (TupleDescAttr(tupdesc, attnum - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
            ereport(ERROR,
                    errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                    errmsg("cannot use virtual generated column \"%s\" in publication column list",
                           colname));
 
        if (bms_is_member(attnum, set))
            ereport(ERROR,
                    errcode(ERRCODE_DUPLICATE_OBJECT),
                    errmsg("duplicate column \"%s\" in publication column list",
                           colname));
 
        set = bms_add_member(set, attnum);
    }
 
    return set;
}
 
/*
 * Transform a column list (represented by an array Datum) to a bitmapset.
 *
 * If columns isn't NULL, add the column numbers to that set.
 *
 * If mcxt isn't NULL, build the bitmapset in that context.
 */
Bitmapset *
pub_collist_to_bitmapset(Bitmapset *columns, Datum pubcols, MemoryContext mcxt)
{
    Bitmapset  *result = columns;
    ArrayType  *arr;
    int         nelems;
    int16      *elems;
    MemoryContext oldcxt = NULL;
 
    arr = DatumGetArrayTypeP(pubcols);
    nelems = ARR_DIMS(arr)[0];
    elems = (int16 *) ARR_DATA_PTR(arr);
 
    /* If a memory context was specified, switch to it. */
    if (mcxt)
        oldcxt = MemoryContextSwitchTo(mcxt);
 
    for (int i = 0; i < nelems; i++)
        result = bms_add_member(result, elems[i]);
 
    if (mcxt)
        MemoryContextSwitchTo(oldcxt);
 
    return result;
}
 
/*
 * Returns a bitmap representing the columns of the specified table.
 *
 * Generated columns are included if include_gencols_type is
 * PUBLISH_GENCOLS_STORED.
 */
Bitmapset *
pub_form_cols_map(Relation relation, PublishGencolsType include_gencols_type)
{
    Bitmapset  *result = NULL;
    TupleDesc   desc = RelationGetDescr(relation);
 
    for (int i = 0; i < desc->natts; i++)
    {
        Form_pg_attribute att = TupleDescAttr(desc, i);
 
        if (att->attisdropped)
            continue;
 
        if (att->attgenerated)
        {
            /* We only support replication of STORED generated cols. */
            if (att->attgenerated != ATTRIBUTE_GENERATED_STORED)
                continue;
 
            /* User hasn't requested to replicate STORED generated cols. */
            if (include_gencols_type != PUBLISH_GENCOLS_STORED)
                continue;
        }
 
        result = bms_add_member(result, att->attnum);
    }
 
    return result;
}
 
/*
 * Insert new publication / schema mapping.
 */
ObjectAddress
publication_add_schema(Oid pubid, Oid schemaid, bool if_not_exists)
{
    Relation    rel;
    HeapTuple   tup;
    Datum       values[Natts_pg_publication_namespace];
    bool        nulls[Natts_pg_publication_namespace];
    Oid         psschid;
    Publication *pub = GetPublication(pubid);
    List       *schemaRels = NIL;
    ObjectAddress myself,
                referenced;
 
    rel = table_open(PublicationNamespaceRelationId, RowExclusiveLock);
 
    /*
     * Check for duplicates. Note that this does not really prevent
     * duplicates, it's here just to provide nicer error message in common
     * case. The real protection is the unique key on the catalog.
     */
    if (SearchSysCacheExists2(PUBLICATIONNAMESPACEMAP,
                              ObjectIdGetDatum(schemaid),
                              ObjectIdGetDatum(pubid)))
    {
        table_close(rel, RowExclusiveLock);
 
        if (if_not_exists)
            return InvalidObjectAddress;
 
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("schema \"%s\" is already member of publication \"%s\"",
                        get_namespace_name(schemaid), pub->name)));
    }
 
    check_publication_add_schema(schemaid);
 
    /* Form a tuple */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));
 
    psschid = GetNewOidWithIndex(rel, PublicationNamespaceObjectIndexId,
                                 Anum_pg_publication_namespace_oid);
    values[Anum_pg_publication_namespace_oid - 1] = ObjectIdGetDatum(psschid);
    values[Anum_pg_publication_namespace_pnpubid - 1] =
        ObjectIdGetDatum(pubid);
    values[Anum_pg_publication_namespace_pnnspid - 1] =
        ObjectIdGetDatum(schemaid);
 
    tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
 
    /* Insert tuple into catalog */
    CatalogTupleInsert(rel, tup);
    heap_freetuple(tup);
 
    ObjectAddressSet(myself, PublicationNamespaceRelationId, psschid);
 
    /* Add dependency on the publication */
    ObjectAddressSet(referenced, PublicationRelationId, pubid);
    recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
 
    /* Add dependency on the schema */
    ObjectAddressSet(referenced, NamespaceRelationId, schemaid);
    recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
 
    /* Close the table */
    table_close(rel, RowExclusiveLock);
 
    /*
     * Invalidate relcache so that publication info is rebuilt. See
     * publication_add_relation for why we need to consider all the
     * partitions.
     */
    schemaRels = GetSchemaPublicationRelations(schemaid,
                                               PUBLICATION_PART_ALL);
    InvalidatePublicationRels(schemaRels);
 
    return myself;
}
 
/*
 * Internal function to get the list of publication oids for a relation.
 *
 * If except_flag is true, returns the list of publication that specified the
 * relation in EXCEPT clause; otherwise, returns the list of publications
 * in which relation is included.
 */
static List *
get_relation_publications(Oid relid, bool except_flag)
{
    List       *result = NIL;
    CatCList   *pubrellist;
 
    /* Find all publications associated with the relation. */
    pubrellist = SearchSysCacheList1(PUBLICATIONRELMAP,
                                     ObjectIdGetDatum(relid));
    for (int i = 0; i < pubrellist->n_members; i++)
    {
        HeapTuple   tup = &pubrellist->members[i]->tuple;
        Form_pg_publication_rel pubrel = (Form_pg_publication_rel) GETSTRUCT(tup);
        Oid         pubid = pubrel->prpubid;
 
        if (pubrel->prexcept == except_flag)
            result = lappend_oid(result, pubid);
    }
 
    ReleaseSysCacheList(pubrellist);
 
    return result;
}
 
/*
 * Gets list of publication oids for a relation.
 */
List *
GetRelationIncludedPublications(Oid relid)
{
    return get_relation_publications(relid, false);
}
 
/*
 * Gets list of publication oids which has relation in EXCEPT clause.
 */
List *
GetRelationExcludedPublications(Oid relid)
{
    return get_relation_publications(relid, true);
}
 
/*
 * Internal function to get the list of relation oids for a publication.
 *
 * If except_flag is true, returns the list of relations specified in the
 * EXCEPT clause of the publication; otherwise, returns the list of relations
 * included in the publication.
 */
static List *
get_publication_relations(Oid pubid, PublicationPartOpt pub_partopt,
                          bool except_flag)
{
    List       *result;
    Relation    pubrelsrel;
    ScanKeyData scankey;
    SysScanDesc scan;
    HeapTuple   tup;
 
    /* Find all relations associated with the publication. */
    pubrelsrel = table_open(PublicationRelRelationId, AccessShareLock);
 
    ScanKeyInit(&scankey,
                Anum_pg_publication_rel_prpubid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(pubid));
 
    scan = systable_beginscan(pubrelsrel, PublicationRelPrpubidIndexId,
                              true, NULL, 1, &scankey);
 
    result = NIL;
    while (HeapTupleIsValid(tup = systable_getnext(scan)))
    {
        Form_pg_publication_rel pubrel;
 
        pubrel = (Form_pg_publication_rel) GETSTRUCT(tup);
 
        if (except_flag == pubrel->prexcept)
            result = GetPubPartitionOptionRelations(result, pub_partopt,
                                                    pubrel->prrelid);
    }
 
    systable_endscan(scan);
    table_close(pubrelsrel, AccessShareLock);
 
    /* Now sort and de-duplicate the result list */
    list_sort(result, list_oid_cmp);
    list_deduplicate_oid(result);
 
    return result;
}
 
/*
 * Gets list of relation oids that are associated with a publication.
 *
 * This should only be used FOR TABLE publications, the FOR ALL TABLES/SEQUENCES
 * should use GetAllPublicationRelations().
 */
List *
GetIncludedPublicationRelations(Oid pubid, PublicationPartOpt pub_partopt)
{
    Assert(!GetPublication(pubid)->alltables);
 
    return get_publication_relations(pubid, pub_partopt, false);
}
 
/*
 * Gets list of table oids that were specified in the EXCEPT clause for a
 * publication.
 *
 * This should only be used FOR ALL TABLES publications.
 */
List *
GetExcludedPublicationTables(Oid pubid, PublicationPartOpt pub_partopt)
{
    Assert(GetPublication(pubid)->alltables);
 
    return get_publication_relations(pubid, pub_partopt, true);
}
 
/*
 * Gets list of publication oids for publications marked as FOR ALL TABLES.
 */
List *
GetAllTablesPublications(void)
{
    List       *result;
    Relation    rel;
    ScanKeyData scankey;
    SysScanDesc scan;
    HeapTuple   tup;
 
    /* Find all publications that are marked as for all tables. */
    rel = table_open(PublicationRelationId, AccessShareLock);
 
    ScanKeyInit(&scankey,
                Anum_pg_publication_puballtables,
                BTEqualStrategyNumber, F_BOOLEQ,
                BoolGetDatum(true));
 
    scan = systable_beginscan(rel, InvalidOid, false,
                              NULL, 1, &scankey);
 
    result = NIL;
    while (HeapTupleIsValid(tup = systable_getnext(scan)))
    {
        Oid         oid = ((Form_pg_publication) GETSTRUCT(tup))->oid;
 
        result = lappend_oid(result, oid);
    }
 
    systable_endscan(scan);
    table_close(rel, AccessShareLock);
 
    return result;
}
 
/*
 * Gets list of all relations published by FOR ALL TABLES/SEQUENCES
 * publication.
 *
 * If the publication publishes partition changes via their respective root
 * partitioned tables, we must exclude partitions in favor of including the
 * root partitioned tables. This is not applicable to FOR ALL SEQUENCES
 * publication.
 *
 * For a FOR ALL TABLES publication, the returned list excludes tables mentioned
 * in EXCEPT TABLE clause.
 */
List *
GetAllPublicationRelations(Oid pubid, char relkind, bool pubviaroot)
{
    Relation    classRel;
    ScanKeyData key[1];
    TableScanDesc scan;
    HeapTuple   tuple;
    List       *result = NIL;
    List       *exceptlist = NIL;
 
    Assert(!(relkind == RELKIND_SEQUENCE && pubviaroot));
 
    /* EXCEPT filtering applies only to relations, not sequences */
    if (relkind == RELKIND_RELATION)
        exceptlist = GetExcludedPublicationTables(pubid, pubviaroot ?
                                                  PUBLICATION_PART_ROOT :
                                                  PUBLICATION_PART_LEAF);
 
    classRel = table_open(RelationRelationId, AccessShareLock);
 
    ScanKeyInit(&key[0],
                Anum_pg_class_relkind,
                BTEqualStrategyNumber, F_CHAREQ,
                CharGetDatum(relkind));
 
    scan = table_beginscan_catalog(classRel, 1, key);
 
    while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    {
        Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple);
        Oid         relid = relForm->oid;
 
        if (is_publishable_class(relid, relForm) &&
            !(relForm->relispartition && pubviaroot) &&
            !list_member_oid(exceptlist, relid))
            result = lappend_oid(result, relid);
    }
 
    table_endscan(scan);
 
    if (pubviaroot)
    {
        ScanKeyInit(&key[0],
                    Anum_pg_class_relkind,
                    BTEqualStrategyNumber, F_CHAREQ,
                    CharGetDatum(RELKIND_PARTITIONED_TABLE));
 
        scan = table_beginscan_catalog(classRel, 1, key);
 
        while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
        {
            Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple);
            Oid         relid = relForm->oid;
 
            if (is_publishable_class(relid, relForm) &&
                !relForm->relispartition &&
                !list_member_oid(exceptlist, relid))
                result = lappend_oid(result, relid);
        }
 
        table_endscan(scan);
    }
 
    table_close(classRel, AccessShareLock);
    return result;
}
 
/*
 * Gets the list of schema oids for a publication.
 *
 * This should only be used FOR TABLES IN SCHEMA publications.
 */
List *
GetPublicationSchemas(Oid pubid)
{
    List       *result = NIL;
    Relation    pubschsrel;
    ScanKeyData scankey;
    SysScanDesc scan;
    HeapTuple   tup;
 
    /* Find all schemas associated with the publication */
    pubschsrel = table_open(PublicationNamespaceRelationId, AccessShareLock);
 
    ScanKeyInit(&scankey,
                Anum_pg_publication_namespace_pnpubid,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(pubid));
 
    scan = systable_beginscan(pubschsrel,
                              PublicationNamespacePnnspidPnpubidIndexId,
                              true, NULL, 1, &scankey);
    while (HeapTupleIsValid(tup = systable_getnext(scan)))
    {
        Form_pg_publication_namespace pubsch;
 
        pubsch = (Form_pg_publication_namespace) GETSTRUCT(tup);
 
        result = lappend_oid(result, pubsch->pnnspid);
    }
 
    systable_endscan(scan);
    table_close(pubschsrel, AccessShareLock);
 
    return result;
}
 
/*
 * Gets the list of publication oids associated with a specified schema.
 */
List *
GetSchemaPublications(Oid schemaid)
{
    List       *result = NIL;
    CatCList   *pubschlist;
    int         i;
 
    /* Find all publications associated with the schema */
    pubschlist = SearchSysCacheList1(PUBLICATIONNAMESPACEMAP,
                                     ObjectIdGetDatum(schemaid));
    for (i = 0; i < pubschlist->n_members; i++)
    {
        HeapTuple   tup = &pubschlist->members[i]->tuple;
        Oid         pubid = ((Form_pg_publication_namespace) GETSTRUCT(tup))->pnpubid;
 
        result = lappend_oid(result, pubid);
    }
 
    ReleaseSysCacheList(pubschlist);
 
    return result;
}
 
/*
 * Get the list of publishable relation oids for a specified schema.
 */
List *
GetSchemaPublicationRelations(Oid schemaid, PublicationPartOpt pub_partopt)
{
    Relation    classRel;
    ScanKeyData key[1];
    TableScanDesc scan;
    HeapTuple   tuple;
    List       *result = NIL;
 
    Assert(OidIsValid(schemaid));
 
    classRel = table_open(RelationRelationId, AccessShareLock);
 
    ScanKeyInit(&key[0],
                Anum_pg_class_relnamespace,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(schemaid));
 
    /* get all the relations present in the specified schema */
    scan = table_beginscan_catalog(classRel, 1, key);
    while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    {
        Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple);
        Oid         relid = relForm->oid;
        char        relkind;
 
        if (!is_publishable_class(relid, relForm))
            continue;
 
        relkind = get_rel_relkind(relid);
        if (relkind == RELKIND_RELATION)
            result = lappend_oid(result, relid);
        else if (relkind == RELKIND_PARTITIONED_TABLE)
        {
            List       *partitionrels = NIL;
 
            /*
             * It is quite possible that some of the partitions are in a
             * different schema than the parent table, so we need to get such
             * partitions separately.
             */
            partitionrels = GetPubPartitionOptionRelations(partitionrels,
                                                           pub_partopt,
                                                           relForm->oid);
            result = list_concat_unique_oid(result, partitionrels);
        }
    }
 
    table_endscan(scan);
    table_close(classRel, AccessShareLock);
    return result;
}
 
/*
 * Gets the list of all relations published by FOR TABLES IN SCHEMA
 * publication.
 */
List *
GetAllSchemaPublicationRelations(Oid pubid, PublicationPartOpt pub_partopt)
{
    List       *result = NIL;
    List       *pubschemalist = GetPublicationSchemas(pubid);
    ListCell   *cell;
 
    foreach(cell, pubschemalist)
    {
        Oid         schemaid = lfirst_oid(cell);
        List       *schemaRels = NIL;
 
        schemaRels = GetSchemaPublicationRelations(schemaid, pub_partopt);
        result = list_concat(result, schemaRels);
    }
 
    return result;
}
 
/*
 * Get publication using oid
 *
 * The Publication struct and its data are palloc'ed here.
 */
Publication *
GetPublication(Oid pubid)
{
    HeapTuple   tup;
    Publication *pub;
    Form_pg_publication pubform;
 
    tup = SearchSysCache1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
    if (!HeapTupleIsValid(tup))
        elog(ERROR, "cache lookup failed for publication %u", pubid);
 
    pubform = (Form_pg_publication) GETSTRUCT(tup);
 
    pub = palloc_object(Publication);
    pub->oid = pubid;
    pub->name = pstrdup(NameStr(pubform->pubname));
    pub->alltables = pubform->puballtables;
    pub->allsequences = pubform->puballsequences;
    pub->pubactions.pubinsert = pubform->pubinsert;
    pub->pubactions.pubupdate = pubform->pubupdate;
    pub->pubactions.pubdelete = pubform->pubdelete;
    pub->pubactions.pubtruncate = pubform->pubtruncate;
    pub->pubviaroot = pubform->pubviaroot;
    pub->pubgencols_type = pubform->pubgencols;
 
    ReleaseSysCache(tup);
 
    return pub;
}
 
/*
 * Get Publication using name.
 */
Publication *
GetPublicationByName(const char *pubname, bool missing_ok)
{
    Oid         oid;
 
    oid = get_publication_oid(pubname, missing_ok);
 
    return OidIsValid(oid) ? GetPublication(oid) : NULL;
}
 
/*
 * Get information of the tables in the given publication array.
 *
 * Returns pubid, relid, column list, row filter for each table.
 */
Datum
pg_get_publication_tables(PG_FUNCTION_ARGS)
{
#define NUM_PUBLICATION_TABLES_ELEM 4
    FuncCallContext *funcctx;
    List       *table_infos = NIL;
 
    /* stuff done only on the first call of the function */
    if (SRF_IS_FIRSTCALL())
    {
        TupleDesc   tupdesc;
        MemoryContext oldcontext;
        ArrayType  *arr;
        Datum      *elems;
        int         nelems,
                    i;
        bool        viaroot = false;
 
        /* create a function context for cross-call persistence */
        funcctx = SRF_FIRSTCALL_INIT();
 
        /* switch to memory context appropriate for multiple function calls */
        oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
        /*
         * Deconstruct the parameter into elements where each element is a
         * publication name.
         */
        arr = PG_GETARG_ARRAYTYPE_P(0);
        deconstruct_array_builtin(arr, TEXTOID, &elems, NULL, &nelems);
 
        /* Get Oids of tables from each publication. */
        for (i = 0; i < nelems; i++)
        {
            Publication *pub_elem;
            List       *pub_elem_tables = NIL;
            ListCell   *lc;
 
            pub_elem = GetPublicationByName(TextDatumGetCString(elems[i]), false);
 
            /*
             * Publications support partitioned tables. If
             * publish_via_partition_root is false, all changes are replicated
             * using leaf partition identity and schema, so we only need
             * those. Otherwise, get the partitioned table itself.
             */
            if (pub_elem->alltables)
                pub_elem_tables = GetAllPublicationRelations(pub_elem->oid,
                                                             RELKIND_RELATION,
                                                             pub_elem->pubviaroot);
            else
            {
                List       *relids,
                           *schemarelids;
 
                relids = GetIncludedPublicationRelations(pub_elem->oid,
                                                         pub_elem->pubviaroot ?
                                                         PUBLICATION_PART_ROOT :
                                                         PUBLICATION_PART_LEAF);
                schemarelids = GetAllSchemaPublicationRelations(pub_elem->oid,
                                                                pub_elem->pubviaroot ?
                                                                PUBLICATION_PART_ROOT :
                                                                PUBLICATION_PART_LEAF);
                pub_elem_tables = list_concat_unique_oid(relids, schemarelids);
            }
 
            /*
             * Record the published table and the corresponding publication so
             * that we can get row filters and column lists later.
             *
             * When a table is published by multiple publications, to obtain
             * all row filters and column lists, the structure related to this
             * table will be recorded multiple times.
             */
            foreach(lc, pub_elem_tables)
            {
                published_rel *table_info = palloc_object(published_rel);
 
                table_info->relid = lfirst_oid(lc);
                table_info->pubid = pub_elem->oid;
                table_infos = lappend(table_infos, table_info);
            }
 
            /* At least one publication is using publish_via_partition_root. */
            if (pub_elem->pubviaroot)
                viaroot = true;
        }
 
        /*
         * If the publication publishes partition changes via their respective
         * root partitioned tables, we must exclude partitions in favor of
         * including the root partitioned tables. Otherwise, the function
         * could return both the child and parent tables which could cause
         * data of the child table to be double-published on the subscriber
         * side.
         */
        if (viaroot)
            filter_partitions(table_infos);
 
        /* Construct a tuple descriptor for the result rows. */
        tupdesc = CreateTemplateTupleDesc(NUM_PUBLICATION_TABLES_ELEM);
        TupleDescInitEntry(tupdesc, (AttrNumber) 1, "pubid",
                           OIDOID, -1, 0);
        TupleDescInitEntry(tupdesc, (AttrNumber) 2, "relid",
                           OIDOID, -1, 0);
        TupleDescInitEntry(tupdesc, (AttrNumber) 3, "attrs",
                           INT2VECTOROID, -1, 0);
        TupleDescInitEntry(tupdesc, (AttrNumber) 4, "qual",
                           PG_NODE_TREEOID, -1, 0);
 
        TupleDescFinalize(tupdesc);
        funcctx->tuple_desc = BlessTupleDesc(tupdesc);
        funcctx->user_fctx = table_infos;
 
        MemoryContextSwitchTo(oldcontext);
    }
 
    /* stuff done on every call of the function */
    funcctx = SRF_PERCALL_SETUP();
    table_infos = (List *) funcctx->user_fctx;
 
    if (funcctx->call_cntr < list_length(table_infos))
    {
        HeapTuple   pubtuple = NULL;
        HeapTuple   rettuple;
        Publication *pub;
        published_rel *table_info = (published_rel *) list_nth(table_infos, funcctx->call_cntr);
        Oid         relid = table_info->relid;
        Oid         schemaid = get_rel_namespace(relid);
        Datum       values[NUM_PUBLICATION_TABLES_ELEM] = {0};
        bool        nulls[NUM_PUBLICATION_TABLES_ELEM] = {0};
 
        /*
         * Form tuple with appropriate data.
         */
 
        pub = GetPublication(table_info->pubid);
 
        values[0] = ObjectIdGetDatum(pub->oid);
        values[1] = ObjectIdGetDatum(relid);
 
        /*
         * We don't consider row filters or column lists for FOR ALL TABLES or
         * FOR TABLES IN SCHEMA publications.
         */
        if (!pub->alltables &&
            !SearchSysCacheExists2(PUBLICATIONNAMESPACEMAP,
                                   ObjectIdGetDatum(schemaid),
                                   ObjectIdGetDatum(pub->oid)))
            pubtuple = SearchSysCacheCopy2(PUBLICATIONRELMAP,
                                           ObjectIdGetDatum(relid),
                                           ObjectIdGetDatum(pub->oid));
 
        if (HeapTupleIsValid(pubtuple))
        {
            /* Lookup the column list attribute. */
            values[2] = SysCacheGetAttr(PUBLICATIONRELMAP, pubtuple,
                                        Anum_pg_publication_rel_prattrs,
                                        &(nulls[2]));
 
            /* Null indicates no filter. */
            values[3] = SysCacheGetAttr(PUBLICATIONRELMAP, pubtuple,
                                        Anum_pg_publication_rel_prqual,
                                        &(nulls[3]));
        }
        else
        {
            nulls[2] = true;
            nulls[3] = true;
        }
 
        /* Show all columns when the column list is not specified. */
        if (nulls[2])
        {
            Relation    rel = table_open(relid, AccessShareLock);
            int         nattnums = 0;
            int16      *attnums;
            TupleDesc   desc = RelationGetDescr(rel);
            int         i;
 
            attnums = palloc_array(int16, desc->natts);
 
            for (i = 0; i < desc->natts; i++)
            {
                Form_pg_attribute att = TupleDescAttr(desc, i);
 
                if (att->attisdropped)
                    continue;
 
                if (att->attgenerated)
                {
                    /* We only support replication of STORED generated cols. */
                    if (att->attgenerated != ATTRIBUTE_GENERATED_STORED)
                        continue;
 
                    /*
                     * User hasn't requested to replicate STORED generated
                     * cols.
                     */
                    if (pub->pubgencols_type != PUBLISH_GENCOLS_STORED)
                        continue;
                }
 
                attnums[nattnums++] = att->attnum;
            }
 
            if (nattnums > 0)
            {
                values[2] = PointerGetDatum(buildint2vector(attnums, nattnums));
                nulls[2] = false;
            }
 
            table_close(rel, AccessShareLock);
        }
 
        rettuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
 
        SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(rettuple));
    }
 
    SRF_RETURN_DONE(funcctx);
}
 
/*
 * Returns Oids of sequences in a publication.
 */
Datum
pg_get_publication_sequences(PG_FUNCTION_ARGS)
{
    FuncCallContext *funcctx;
    List       *sequences = NIL;
 
    /* stuff done only on the first call of the function */
    if (SRF_IS_FIRSTCALL())
    {
        char       *pubname = text_to_cstring(PG_GETARG_TEXT_PP(0));
        Publication *publication;
        MemoryContext oldcontext;
 
        /* create a function context for cross-call persistence */
        funcctx = SRF_FIRSTCALL_INIT();
 
        /* switch to memory context appropriate for multiple function calls */
        oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
        publication = GetPublicationByName(pubname, false);
 
        if (publication->allsequences)
            sequences = GetAllPublicationRelations(publication->oid,
                                                   RELKIND_SEQUENCE,
                                                   false);
 
        funcctx->user_fctx = sequences;
 
        MemoryContextSwitchTo(oldcontext);
    }
 
    /* stuff done on every call of the function */
    funcctx = SRF_PERCALL_SETUP();
    sequences = (List *) funcctx->user_fctx;
 
    if (funcctx->call_cntr < list_length(sequences))
    {
        Oid         relid = list_nth_oid(sequences, funcctx->call_cntr);
 
        SRF_RETURN_NEXT(funcctx, ObjectIdGetDatum(relid));
    }
 
    SRF_RETURN_DONE(funcctx);
}