opclasscmds.c

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/*-------------------------------------------------------------------------
 *
 * opclasscmds.c
 *
 *    Routines for opclass (and opfamily) manipulation commands
 *
 * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/commands/opclasscmds.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include <limits.h>

#include "access/genam.h"
#include "access/hash.h"
#include "access/heapam.h"
#include "access/nbtree.h"
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.h"
#include "catalog/opfam_internal.h"
#include "catalog/pg_am.h"
#include "catalog/pg_amop.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/alter.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "miscadmin.h"
#include "parser/parse_func.h"
#include "parser/parse_oper.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
#include "utils/tqual.h"


static void AlterOpFamilyAdd(AlterOpFamilyStmt *stmt,
                 Oid amoid, Oid opfamilyoid,
                 int maxOpNumber, int maxProcNumber,
                 List *items);
static void AlterOpFamilyDrop(AlterOpFamilyStmt *stmt,
                  Oid amoid, Oid opfamilyoid,
                  int maxOpNumber, int maxProcNumber,
                  List *items);
static void processTypesSpec(List *args, Oid *lefttype, Oid *righttype);
static void assignOperTypes(OpFamilyMember *member, Oid amoid, Oid typeoid);
static void assignProcTypes(OpFamilyMember *member, Oid amoid, Oid typeoid);
static void addFamilyMember(List **list, OpFamilyMember *member, bool isProc);
static void storeOperators(List *opfamilyname, Oid amoid,
               Oid opfamilyoid, Oid opclassoid,
               List *operators, bool isAdd);
static void storeProcedures(List *opfamilyname, Oid amoid,
                Oid opfamilyoid, Oid opclassoid,
                List *procedures, bool isAdd);
static void dropOperators(List *opfamilyname, Oid amoid, Oid opfamilyoid,
              List *operators);
static void dropProcedures(List *opfamilyname, Oid amoid, Oid opfamilyoid,
               List *procedures);

/*
 * OpFamilyCacheLookup
 *      Look up an existing opfamily by name.
 *
 * Returns a syscache tuple reference, or NULL if not found.
 */
static HeapTuple
OpFamilyCacheLookup(Oid amID, List *opfamilyname, bool missing_ok)
{
    char       *schemaname;
    char       *opfname;
    HeapTuple   htup;

    /* deconstruct the name list */
    DeconstructQualifiedName(opfamilyname, &schemaname, &opfname);

    if (schemaname)
    {
        /* Look in specific schema only */
        Oid         namespaceId;

        namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
        if (!OidIsValid(namespaceId))
            htup = NULL;
        else
            htup = SearchSysCache3(OPFAMILYAMNAMENSP,
                                   ObjectIdGetDatum(amID),
                                   PointerGetDatum(opfname),
                                   ObjectIdGetDatum(namespaceId));
    }
    else
    {
        /* Unqualified opfamily name, so search the search path */
        Oid         opfID = OpfamilynameGetOpfid(amID, opfname);

        if (!OidIsValid(opfID))
            htup = NULL;
        else
            htup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfID));
    }

    if (!HeapTupleIsValid(htup) && !missing_ok)
    {
        HeapTuple   amtup;

        amtup = SearchSysCache1(AMOID, ObjectIdGetDatum(amID));
        if (!HeapTupleIsValid(amtup))
            elog(ERROR, "cache lookup failed for access method %u", amID);
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("operator family \"%s\" does not exist for access method \"%s\"",
                        NameListToString(opfamilyname),
                        NameStr(((Form_pg_am) GETSTRUCT(amtup))->amname))));
    }

    return htup;
}

/*
 * get_opfamily_oid
 *    find an opfamily OID by possibly qualified name
 *
 * If not found, returns InvalidOid if missing_ok, else throws error.
 */
Oid
get_opfamily_oid(Oid amID, List *opfamilyname, bool missing_ok)
{
    HeapTuple   htup;
    Oid         opfID;

    htup = OpFamilyCacheLookup(amID, opfamilyname, missing_ok);
    if (!HeapTupleIsValid(htup))
        return InvalidOid;
    opfID = HeapTupleGetOid(htup);
    ReleaseSysCache(htup);

    return opfID;
}

/*
 * OpClassCacheLookup
 *      Look up an existing opclass by name.
 *
 * Returns a syscache tuple reference, or NULL if not found.
 */
static HeapTuple
OpClassCacheLookup(Oid amID, List *opclassname, bool missing_ok)
{
    char       *schemaname;
    char       *opcname;
    HeapTuple   htup;

    /* deconstruct the name list */
    DeconstructQualifiedName(opclassname, &schemaname, &opcname);

    if (schemaname)
    {
        /* Look in specific schema only */
        Oid         namespaceId;

        namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
        if (!OidIsValid(namespaceId))
            htup = NULL;
        else
            htup = SearchSysCache3(CLAAMNAMENSP,
                                   ObjectIdGetDatum(amID),
                                   PointerGetDatum(opcname),
                                   ObjectIdGetDatum(namespaceId));
    }
    else
    {
        /* Unqualified opclass name, so search the search path */
        Oid         opcID = OpclassnameGetOpcid(amID, opcname);

        if (!OidIsValid(opcID))
            htup = NULL;
        else
            htup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opcID));
    }

    if (!HeapTupleIsValid(htup) && !missing_ok)
    {
        HeapTuple   amtup;

        amtup = SearchSysCache1(AMOID, ObjectIdGetDatum(amID));
        if (!HeapTupleIsValid(amtup))
            elog(ERROR, "cache lookup failed for access method %u", amID);
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("operator class \"%s\" does not exist for access method \"%s\"",
                        NameListToString(opclassname),
                        NameStr(((Form_pg_am) GETSTRUCT(amtup))->amname))));
    }

    return htup;
}

/*
 * get_opclass_oid
 *    find an opclass OID by possibly qualified name
 *
 * If not found, returns InvalidOid if missing_ok, else throws error.
 */
Oid
get_opclass_oid(Oid amID, List *opclassname, bool missing_ok)
{
    HeapTuple   htup;
    Oid         opcID;

    htup = OpClassCacheLookup(amID, opclassname, missing_ok);
    if (!HeapTupleIsValid(htup))
        return InvalidOid;
    opcID = HeapTupleGetOid(htup);
    ReleaseSysCache(htup);

    return opcID;
}

/*
 * CreateOpFamily
 *      Internal routine to make the catalog entry for a new operator family.
 *
 * Caller must have done permissions checks etc. already.
 */
static ObjectAddress
CreateOpFamily(const char *amname, const char *opfname, Oid namespaceoid, Oid amoid)
{
    Oid         opfamilyoid;
    Relation    rel;
    HeapTuple   tup;
    Datum       values[Natts_pg_opfamily];
    bool        nulls[Natts_pg_opfamily];
    NameData    opfName;
    ObjectAddress myself,
                referenced;

    rel = heap_open(OperatorFamilyRelationId, RowExclusiveLock);

    /*
     * Make sure there is no existing opfamily of this name (this is just to
     * give a more friendly error message than "duplicate key").
     */
    if (SearchSysCacheExists3(OPFAMILYAMNAMENSP,
                              ObjectIdGetDatum(amoid),
                              CStringGetDatum(opfname),
                              ObjectIdGetDatum(namespaceoid)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("operator family \"%s\" for access method \"%s\" already exists",
                        opfname, amname)));

    /*
     * Okay, let's create the pg_opfamily entry.
     */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));

    values[Anum_pg_opfamily_opfmethod - 1] = ObjectIdGetDatum(amoid);
    namestrcpy(&opfName, opfname);
    values[Anum_pg_opfamily_opfname - 1] = NameGetDatum(&opfName);
    values[Anum_pg_opfamily_opfnamespace - 1] = ObjectIdGetDatum(namespaceoid);
    values[Anum_pg_opfamily_opfowner - 1] = ObjectIdGetDatum(GetUserId());

    tup = heap_form_tuple(rel->rd_att, values, nulls);

    opfamilyoid = CatalogTupleInsert(rel, tup);

    heap_freetuple(tup);

    /*
     * Create dependencies for the opfamily proper.
     */
    myself.classId = OperatorFamilyRelationId;
    myself.objectId = opfamilyoid;
    myself.objectSubId = 0;

    /* dependency on access method */
    referenced.classId = AccessMethodRelationId;
    referenced.objectId = amoid;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);

    /* dependency on namespace */
    referenced.classId = NamespaceRelationId;
    referenced.objectId = namespaceoid;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* dependency on owner */
    recordDependencyOnOwner(OperatorFamilyRelationId, opfamilyoid, GetUserId());

    /* dependency on extension */
    recordDependencyOnCurrentExtension(&myself, false);

    /* Post creation hook for new operator family */
    InvokeObjectPostCreateHook(OperatorFamilyRelationId, opfamilyoid, 0);

    heap_close(rel, RowExclusiveLock);

    return myself;
}

/*
 * DefineOpClass
 *      Define a new index operator class.
 */
ObjectAddress
DefineOpClass(CreateOpClassStmt *stmt)
{
    char       *opcname;        /* name of opclass we're creating */
    Oid         amoid,          /* our AM's oid */
                typeoid,        /* indexable datatype oid */
                storageoid,     /* storage datatype oid, if any */
                namespaceoid,   /* namespace to create opclass in */
                opfamilyoid,    /* oid of containing opfamily */
                opclassoid;     /* oid of opclass we create */
    int         maxOpNumber,    /* amstrategies value */
                maxProcNumber;  /* amsupport value */
    bool        amstorage;      /* amstorage flag */
    List       *operators;      /* OpFamilyMember list for operators */
    List       *procedures;     /* OpFamilyMember list for support procs */
    ListCell   *l;
    Relation    rel;
    HeapTuple   tup;
    IndexAmRoutine *amroutine;
    Datum       values[Natts_pg_opclass];
    bool        nulls[Natts_pg_opclass];
    AclResult   aclresult;
    NameData    opcName;
    ObjectAddress myself,
                referenced;

    /* Convert list of names to a name and namespace */
    namespaceoid = QualifiedNameGetCreationNamespace(stmt->opclassname,
                                                     &opcname);

    /* Check we have creation rights in target namespace */
    aclresult = pg_namespace_aclcheck(namespaceoid, GetUserId(), ACL_CREATE);
    if (aclresult != ACLCHECK_OK)
        aclcheck_error(aclresult, OBJECT_SCHEMA,
                       get_namespace_name(namespaceoid));

    /* Get necessary info about access method */
    tup = SearchSysCache1(AMNAME, CStringGetDatum(stmt->amname));
    if (!HeapTupleIsValid(tup))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("access method \"%s\" does not exist",
                        stmt->amname)));

    amoid = HeapTupleGetOid(tup);
    amroutine = GetIndexAmRoutineByAmId(amoid, false);
    ReleaseSysCache(tup);

    maxOpNumber = amroutine->amstrategies;
    /* if amstrategies is zero, just enforce that op numbers fit in int16 */
    if (maxOpNumber <= 0)
        maxOpNumber = SHRT_MAX;
    maxProcNumber = amroutine->amsupport;
    amstorage = amroutine->amstorage;

    /* XXX Should we make any privilege check against the AM? */

    /*
     * The question of appropriate permissions for CREATE OPERATOR CLASS is
     * interesting.  Creating an opclass is tantamount to granting public
     * execute access on the functions involved, since the index machinery
     * generally does not check access permission before using the functions.
     * A minimum expectation therefore is that the caller have execute
     * privilege with grant option.  Since we don't have a way to make the
     * opclass go away if the grant option is revoked, we choose instead to
     * require ownership of the functions.  It's also not entirely clear what
     * permissions should be required on the datatype, but ownership seems
     * like a safe choice.
     *
     * Currently, we require superuser privileges to create an opclass. This
     * seems necessary because we have no way to validate that the offered set
     * of operators and functions are consistent with the AM's expectations.
     * It would be nice to provide such a check someday, if it can be done
     * without solving the halting problem :-(
     *
     * XXX re-enable NOT_USED code sections below if you remove this test.
     */
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to create an operator class")));

    /* Look up the datatype */
    typeoid = typenameTypeId(NULL, stmt->datatype);

#ifdef NOT_USED
    /* XXX this is unnecessary given the superuser check above */
    /* Check we have ownership of the datatype */
    if (!pg_type_ownercheck(typeoid, GetUserId()))
        aclcheck_error_type(ACLCHECK_NOT_OWNER, typeoid);
#endif

    /*
     * Look up the containing operator family, or create one if FAMILY option
     * was omitted and there's not a match already.
     */
    if (stmt->opfamilyname)
    {
        opfamilyoid = get_opfamily_oid(amoid, stmt->opfamilyname, false);
    }
    else
    {
        /* Lookup existing family of same name and namespace */
        tup = SearchSysCache3(OPFAMILYAMNAMENSP,
                              ObjectIdGetDatum(amoid),
                              PointerGetDatum(opcname),
                              ObjectIdGetDatum(namespaceoid));
        if (HeapTupleIsValid(tup))
        {
            opfamilyoid = HeapTupleGetOid(tup);

            /*
             * XXX given the superuser check above, there's no need for an
             * ownership check here
             */
            ReleaseSysCache(tup);
        }
        else
        {
            ObjectAddress tmpAddr;

            /*
             * Create it ... again no need for more permissions ...
             */
            tmpAddr = CreateOpFamily(stmt->amname, opcname,
                                     namespaceoid, amoid);
            opfamilyoid = tmpAddr.objectId;
        }
    }

    operators = NIL;
    procedures = NIL;

    /* Storage datatype is optional */
    storageoid = InvalidOid;

    /*
     * Scan the "items" list to obtain additional info.
     */
    foreach(l, stmt->items)
    {
        CreateOpClassItem *item = lfirst_node(CreateOpClassItem, l);
        Oid         operOid;
        Oid         funcOid;
        Oid         sortfamilyOid;
        OpFamilyMember *member;

        switch (item->itemtype)
        {
            case OPCLASS_ITEM_OPERATOR:
                if (item->number <= 0 || item->number > maxOpNumber)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("invalid operator number %d,"
                                    " must be between 1 and %d",
                                    item->number, maxOpNumber)));
                if (item->name->objargs != NIL)
                    operOid = LookupOperWithArgs(item->name, false);
                else
                {
                    /* Default to binary op on input datatype */
                    operOid = LookupOperName(NULL, item->name->objname,
                                             typeoid, typeoid,
                                             false, -1);
                }

                if (item->order_family)
                    sortfamilyOid = get_opfamily_oid(BTREE_AM_OID,
                                                     item->order_family,
                                                     false);
                else
                    sortfamilyOid = InvalidOid;

#ifdef NOT_USED
                /* XXX this is unnecessary given the superuser check above */
                /* Caller must own operator and its underlying function */
                if (!pg_oper_ownercheck(operOid, GetUserId()))
                    aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_OPERATOR,
                                   get_opname(operOid));
                funcOid = get_opcode(operOid);
                if (!pg_proc_ownercheck(funcOid, GetUserId()))
                    aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_FUNCTION,
                                   get_func_name(funcOid));
#endif

                /* Save the info */
                member = (OpFamilyMember *) palloc0(sizeof(OpFamilyMember));
                member->object = operOid;
                member->number = item->number;
                member->sortfamily = sortfamilyOid;
                assignOperTypes(member, amoid, typeoid);
                addFamilyMember(&operators, member, false);
                break;
            case OPCLASS_ITEM_FUNCTION:
                if (item->number <= 0 || item->number > maxProcNumber)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("invalid procedure number %d,"
                                    " must be between 1 and %d",
                                    item->number, maxProcNumber)));
                funcOid = LookupFuncWithArgs(OBJECT_FUNCTION, item->name, false);
#ifdef NOT_USED
                /* XXX this is unnecessary given the superuser check above */
                /* Caller must own function */
                if (!pg_proc_ownercheck(funcOid, GetUserId()))
                    aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_FUNCTION,
                                   get_func_name(funcOid));
#endif

                /* Save the info */
                member = (OpFamilyMember *) palloc0(sizeof(OpFamilyMember));
                member->object = funcOid;
                member->number = item->number;

                /* allow overriding of the function's actual arg types */
                if (item->class_args)
                    processTypesSpec(item->class_args,
                                     &member->lefttype, &member->righttype);

                assignProcTypes(member, amoid, typeoid);
                addFamilyMember(&procedures, member, true);
                break;
            case OPCLASS_ITEM_STORAGETYPE:
                if (OidIsValid(storageoid))
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("storage type specified more than once")));
                storageoid = typenameTypeId(NULL, item->storedtype);

#ifdef NOT_USED
                /* XXX this is unnecessary given the superuser check above */
                /* Check we have ownership of the datatype */
                if (!pg_type_ownercheck(storageoid, GetUserId()))
                    aclcheck_error_type(ACLCHECK_NOT_OWNER, storageoid);
#endif
                break;
            default:
                elog(ERROR, "unrecognized item type: %d", item->itemtype);
                break;
        }
    }

    /*
     * If storagetype is specified, make sure it's legal.
     */
    if (OidIsValid(storageoid))
    {
        /* Just drop the spec if same as column datatype */
        if (storageoid == typeoid)
            storageoid = InvalidOid;
        else if (!amstorage)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("storage type cannot be different from data type for access method \"%s\"",
                            stmt->amname)));
    }

    rel = heap_open(OperatorClassRelationId, RowExclusiveLock);

    /*
     * Make sure there is no existing opclass of this name (this is just to
     * give a more friendly error message than "duplicate key").
     */
    if (SearchSysCacheExists3(CLAAMNAMENSP,
                              ObjectIdGetDatum(amoid),
                              CStringGetDatum(opcname),
                              ObjectIdGetDatum(namespaceoid)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("operator class \"%s\" for access method \"%s\" already exists",
                        opcname, stmt->amname)));

    /*
     * If we are creating a default opclass, check there isn't one already.
     * (Note we do not restrict this test to visible opclasses; this ensures
     * that typcache.c can find unique solutions to its questions.)
     */
    if (stmt->isDefault)
    {
        ScanKeyData skey[1];
        SysScanDesc scan;

        ScanKeyInit(&skey[0],
                    Anum_pg_opclass_opcmethod,
                    BTEqualStrategyNumber, F_OIDEQ,
                    ObjectIdGetDatum(amoid));

        scan = systable_beginscan(rel, OpclassAmNameNspIndexId, true,
                                  NULL, 1, skey);

        while (HeapTupleIsValid(tup = systable_getnext(scan)))
        {
            Form_pg_opclass opclass = (Form_pg_opclass) GETSTRUCT(tup);

            if (opclass->opcintype == typeoid && opclass->opcdefault)
                ereport(ERROR,
                        (errcode(ERRCODE_DUPLICATE_OBJECT),
                         errmsg("could not make operator class \"%s\" be default for type %s",
                                opcname,
                                TypeNameToString(stmt->datatype)),
                         errdetail("Operator class \"%s\" already is the default.",
                                   NameStr(opclass->opcname))));
        }

        systable_endscan(scan);
    }

    /*
     * Okay, let's create the pg_opclass entry.
     */
    memset(values, 0, sizeof(values));
    memset(nulls, false, sizeof(nulls));

    values[Anum_pg_opclass_opcmethod - 1] = ObjectIdGetDatum(amoid);
    namestrcpy(&opcName, opcname);
    values[Anum_pg_opclass_opcname - 1] = NameGetDatum(&opcName);
    values[Anum_pg_opclass_opcnamespace - 1] = ObjectIdGetDatum(namespaceoid);
    values[Anum_pg_opclass_opcowner - 1] = ObjectIdGetDatum(GetUserId());
    values[Anum_pg_opclass_opcfamily - 1] = ObjectIdGetDatum(opfamilyoid);
    values[Anum_pg_opclass_opcintype - 1] = ObjectIdGetDatum(typeoid);
    values[Anum_pg_opclass_opcdefault - 1] = BoolGetDatum(stmt->isDefault);
    values[Anum_pg_opclass_opckeytype - 1] = ObjectIdGetDatum(storageoid);

    tup = heap_form_tuple(rel->rd_att, values, nulls);

    opclassoid = CatalogTupleInsert(rel, tup);

    heap_freetuple(tup);

    /*
     * Now add tuples to pg_amop and pg_amproc tying in the operators and
     * functions.  Dependencies on them are inserted, too.
     */
    storeOperators(stmt->opfamilyname, amoid, opfamilyoid,
                   opclassoid, operators, false);
    storeProcedures(stmt->opfamilyname, amoid, opfamilyoid,
                    opclassoid, procedures, false);

    /* let event triggers know what happened */
    EventTriggerCollectCreateOpClass(stmt, opclassoid, operators, procedures);

    /*
     * Create dependencies for the opclass proper.  Note: we do not need a
     * dependency link to the AM, because that exists through the opfamily.
     */
    myself.classId = OperatorClassRelationId;
    myself.objectId = opclassoid;
    myself.objectSubId = 0;

    /* dependency on namespace */
    referenced.classId = NamespaceRelationId;
    referenced.objectId = namespaceoid;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* dependency on opfamily */
    referenced.classId = OperatorFamilyRelationId;
    referenced.objectId = opfamilyoid;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);

    /* dependency on indexed datatype */
    referenced.classId = TypeRelationId;
    referenced.objectId = typeoid;
    referenced.objectSubId = 0;
    recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

    /* dependency on storage datatype */
    if (OidIsValid(storageoid))
    {
        referenced.classId = TypeRelationId;
        referenced.objectId = storageoid;
        referenced.objectSubId = 0;
        recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
    }

    /* dependency on owner */
    recordDependencyOnOwner(OperatorClassRelationId, opclassoid, GetUserId());

    /* dependency on extension */
    recordDependencyOnCurrentExtension(&myself, false);

    /* Post creation hook for new operator class */
    InvokeObjectPostCreateHook(OperatorClassRelationId, opclassoid, 0);

    heap_close(rel, RowExclusiveLock);

    return myself;
}


/*
 * DefineOpFamily
 *      Define a new index operator family.
 */
ObjectAddress
DefineOpFamily(CreateOpFamilyStmt *stmt)
{
    char       *opfname;        /* name of opfamily we're creating */
    Oid         amoid,          /* our AM's oid */
                namespaceoid;   /* namespace to create opfamily in */
    AclResult   aclresult;

    /* Convert list of names to a name and namespace */
    namespaceoid = QualifiedNameGetCreationNamespace(stmt->opfamilyname,
                                                     &opfname);

    /* Check we have creation rights in target namespace */
    aclresult = pg_namespace_aclcheck(namespaceoid, GetUserId(), ACL_CREATE);
    if (aclresult != ACLCHECK_OK)
        aclcheck_error(aclresult, OBJECT_SCHEMA,
                       get_namespace_name(namespaceoid));

    /* Get access method OID, throwing an error if it doesn't exist. */
    amoid = get_index_am_oid(stmt->amname, false);

    /* XXX Should we make any privilege check against the AM? */

    /*
     * Currently, we require superuser privileges to create an opfamily. See
     * comments in DefineOpClass.
     */
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to create an operator family")));

    /* Insert pg_opfamily catalog entry */
    return CreateOpFamily(stmt->amname, opfname, namespaceoid, amoid);
}


/*
 * AlterOpFamily
 *      Add or remove operators/procedures within an existing operator family.
 *
 * Note: this implements only ALTER OPERATOR FAMILY ... ADD/DROP.  Some
 * other commands called ALTER OPERATOR FAMILY exist, but go through
 * different code paths.
 */
Oid
AlterOpFamily(AlterOpFamilyStmt *stmt)
{
    Oid         amoid,          /* our AM's oid */
                opfamilyoid;    /* oid of opfamily */
    int         maxOpNumber,    /* amstrategies value */
                maxProcNumber;  /* amsupport value */
    HeapTuple   tup;
    IndexAmRoutine *amroutine;

    /* Get necessary info about access method */
    tup = SearchSysCache1(AMNAME, CStringGetDatum(stmt->amname));
    if (!HeapTupleIsValid(tup))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("access method \"%s\" does not exist",
                        stmt->amname)));

    amoid = HeapTupleGetOid(tup);
    amroutine = GetIndexAmRoutineByAmId(amoid, false);
    ReleaseSysCache(tup);

    maxOpNumber = amroutine->amstrategies;
    /* if amstrategies is zero, just enforce that op numbers fit in int16 */
    if (maxOpNumber <= 0)
        maxOpNumber = SHRT_MAX;
    maxProcNumber = amroutine->amsupport;

    /* XXX Should we make any privilege check against the AM? */

    /* Look up the opfamily */
    opfamilyoid = get_opfamily_oid(amoid, stmt->opfamilyname, false);

    /*
     * Currently, we require superuser privileges to alter an opfamily.
     *
     * XXX re-enable NOT_USED code sections below if you remove this test.
     */
    if (!superuser())
        ereport(ERROR,
                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                 errmsg("must be superuser to alter an operator family")));

    /*
     * ADD and DROP cases need separate code from here on down.
     */
    if (stmt->isDrop)
        AlterOpFamilyDrop(stmt, amoid, opfamilyoid,
                          maxOpNumber, maxProcNumber, stmt->items);
    else
        AlterOpFamilyAdd(stmt, amoid, opfamilyoid,
                         maxOpNumber, maxProcNumber, stmt->items);

    return opfamilyoid;
}

/*
 * ADD part of ALTER OP FAMILY
 */
static void
AlterOpFamilyAdd(AlterOpFamilyStmt *stmt, Oid amoid, Oid opfamilyoid,
                 int maxOpNumber, int maxProcNumber, List *items)
{
    List       *operators;      /* OpFamilyMember list for operators */
    List       *procedures;     /* OpFamilyMember list for support procs */
    ListCell   *l;

    operators = NIL;
    procedures = NIL;

    /*
     * Scan the "items" list to obtain additional info.
     */
    foreach(l, items)
    {
        CreateOpClassItem *item = lfirst_node(CreateOpClassItem, l);
        Oid         operOid;
        Oid         funcOid;
        Oid         sortfamilyOid;
        OpFamilyMember *member;

        switch (item->itemtype)
        {
            case OPCLASS_ITEM_OPERATOR:
                if (item->number <= 0 || item->number > maxOpNumber)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("invalid operator number %d,"
                                    " must be between 1 and %d",
                                    item->number, maxOpNumber)));
                if (item->name->objargs != NIL)
                    operOid = LookupOperWithArgs(item->name, false);
                else
                {
                    ereport(ERROR,
                            (errcode(ERRCODE_SYNTAX_ERROR),
                             errmsg("operator argument types must be specified in ALTER OPERATOR FAMILY")));
                    operOid = InvalidOid;   /* keep compiler quiet */
                }

                if (item->order_family)
                    sortfamilyOid = get_opfamily_oid(BTREE_AM_OID,
                                                     item->order_family,
                                                     false);
                else
                    sortfamilyOid = InvalidOid;

#ifdef NOT_USED
                /* XXX this is unnecessary given the superuser check above */
                /* Caller must own operator and its underlying function */
                if (!pg_oper_ownercheck(operOid, GetUserId()))
                    aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_OPERATOR,
                                   get_opname(operOid));
                funcOid = get_opcode(operOid);
                if (!pg_proc_ownercheck(funcOid, GetUserId()))
                    aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_FUNCTION,
                                   get_func_name(funcOid));
#endif

                /* Save the info */
                member = (OpFamilyMember *) palloc0(sizeof(OpFamilyMember));
                member->object = operOid;
                member->number = item->number;
                member->sortfamily = sortfamilyOid;
                assignOperTypes(member, amoid, InvalidOid);
                addFamilyMember(&operators, member, false);
                break;
            case OPCLASS_ITEM_FUNCTION:
                if (item->number <= 0 || item->number > maxProcNumber)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("invalid procedure number %d,"
                                    " must be between 1 and %d",
                                    item->number, maxProcNumber)));
                funcOid = LookupFuncWithArgs(OBJECT_FUNCTION, item->name, false);
#ifdef NOT_USED
                /* XXX this is unnecessary given the superuser check above */
                /* Caller must own function */
                if (!pg_proc_ownercheck(funcOid, GetUserId()))
                    aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_FUNCTION,
                                   get_func_name(funcOid));
#endif

                /* Save the info */
                member = (OpFamilyMember *) palloc0(sizeof(OpFamilyMember));
                member->object = funcOid;
                member->number = item->number;

                /* allow overriding of the function's actual arg types */
                if (item->class_args)
                    processTypesSpec(item->class_args,
                                     &member->lefttype, &member->righttype);

                assignProcTypes(member, amoid, InvalidOid);
                addFamilyMember(&procedures, member, true);
                break;
            case OPCLASS_ITEM_STORAGETYPE:
                ereport(ERROR,
                        (errcode(ERRCODE_SYNTAX_ERROR),
                         errmsg("STORAGE cannot be specified in ALTER OPERATOR FAMILY")));
                break;
            default:
                elog(ERROR, "unrecognized item type: %d", item->itemtype);
                break;
        }
    }

    /*
     * Add tuples to pg_amop and pg_amproc tying in the operators and
     * functions.  Dependencies on them are inserted, too.
     */
    storeOperators(stmt->opfamilyname, amoid, opfamilyoid,
                   InvalidOid, operators, true);
    storeProcedures(stmt->opfamilyname, amoid, opfamilyoid,
                    InvalidOid, procedures, true);

    /* make information available to event triggers */
    EventTriggerCollectAlterOpFam(stmt, opfamilyoid,
                                  operators, procedures);
}

/*
 * DROP part of ALTER OP FAMILY
 */
static void
AlterOpFamilyDrop(AlterOpFamilyStmt *stmt, Oid amoid, Oid opfamilyoid,
                  int maxOpNumber, int maxProcNumber, List *items)
{
    List       *operators;      /* OpFamilyMember list for operators */
    List       *procedures;     /* OpFamilyMember list for support procs */
    ListCell   *l;

    operators = NIL;
    procedures = NIL;

    /*
     * Scan the "items" list to obtain additional info.
     */
    foreach(l, items)
    {
        CreateOpClassItem *item = lfirst_node(CreateOpClassItem, l);
        Oid         lefttype,
                    righttype;
        OpFamilyMember *member;

        switch (item->itemtype)
        {
            case OPCLASS_ITEM_OPERATOR:
                if (item->number <= 0 || item->number > maxOpNumber)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("invalid operator number %d,"
                                    " must be between 1 and %d",
                                    item->number, maxOpNumber)));
                processTypesSpec(item->class_args, &lefttype, &righttype);
                /* Save the info */
                member = (OpFamilyMember *) palloc0(sizeof(OpFamilyMember));
                member->number = item->number;
                member->lefttype = lefttype;
                member->righttype = righttype;
                addFamilyMember(&operators, member, false);
                break;
            case OPCLASS_ITEM_FUNCTION:
                if (item->number <= 0 || item->number > maxProcNumber)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("invalid procedure number %d,"
                                    " must be between 1 and %d",
                                    item->number, maxProcNumber)));
                processTypesSpec(item->class_args, &lefttype, &righttype);
                /* Save the info */
                member = (OpFamilyMember *) palloc0(sizeof(OpFamilyMember));
                member->number = item->number;
                member->lefttype = lefttype;
                member->righttype = righttype;
                addFamilyMember(&procedures, member, true);
                break;
            case OPCLASS_ITEM_STORAGETYPE:
                /* grammar prevents this from appearing */
            default:
                elog(ERROR, "unrecognized item type: %d", item->itemtype);
                break;
        }
    }

    /*
     * Remove tuples from pg_amop and pg_amproc.
     */
    dropOperators(stmt->opfamilyname, amoid, opfamilyoid, operators);
    dropProcedures(stmt->opfamilyname, amoid, opfamilyoid, procedures);

    /* make information available to event triggers */
    EventTriggerCollectAlterOpFam(stmt, opfamilyoid,
                                  operators, procedures);
}


/*
 * Deal with explicit arg types used in ALTER ADD/DROP
 */
static void
processTypesSpec(List *args, Oid *lefttype, Oid *righttype)
{
    TypeName   *typeName;

    Assert(args != NIL);

    typeName = (TypeName *) linitial(args);
    *lefttype = typenameTypeId(NULL, typeName);

    if (list_length(args) > 1)
    {
        typeName = (TypeName *) lsecond(args);
        *righttype = typenameTypeId(NULL, typeName);
    }
    else
        *righttype = *lefttype;

    if (list_length(args) > 2)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("one or two argument types must be specified")));
}


/*
 * Determine the lefttype/righttype to assign to an operator,
 * and do any validity checking we can manage.
 */
static void
assignOperTypes(OpFamilyMember *member, Oid amoid, Oid typeoid)
{
    Operator    optup;
    Form_pg_operator opform;

    /* Fetch the operator definition */
    optup = SearchSysCache1(OPEROID, ObjectIdGetDatum(member->object));
    if (optup == NULL)
        elog(ERROR, "cache lookup failed for operator %u", member->object);
    opform = (Form_pg_operator) GETSTRUCT(optup);

    /*
     * Opfamily operators must be binary.
     */
    if (opform->oprkind != 'b')
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("index operators must be binary")));

    if (OidIsValid(member->sortfamily))
    {
        /*
         * Ordering op, check index supports that.  (We could perhaps also
         * check that the operator returns a type supported by the sortfamily,
         * but that seems more trouble than it's worth here.  If it does not,
         * the operator will never be matchable to any ORDER BY clause, but no
         * worse consequences can ensue.  Also, trying to check that would
         * create an ordering hazard during dump/reload: it's possible that
         * the family has been created but not yet populated with the required
         * operators.)
         */
        IndexAmRoutine *amroutine = GetIndexAmRoutineByAmId(amoid, false);

        if (!amroutine->amcanorderbyop)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("access method \"%s\" does not support ordering operators",
                            get_am_name(amoid))));
    }
    else
    {
        /*
         * Search operators must return boolean.
         */
        if (opform->oprresult != BOOLOID)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("index search operators must return boolean")));
    }

    /*
     * If lefttype/righttype isn't specified, use the operator's input types
     */
    if (!OidIsValid(member->lefttype))
        member->lefttype = opform->oprleft;
    if (!OidIsValid(member->righttype))
        member->righttype = opform->oprright;

    ReleaseSysCache(optup);
}

/*
 * Determine the lefttype/righttype to assign to a support procedure,
 * and do any validity checking we can manage.
 */
static void
assignProcTypes(OpFamilyMember *member, Oid amoid, Oid typeoid)
{
    HeapTuple   proctup;
    Form_pg_proc procform;

    /* Fetch the procedure definition */
    proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(member->object));
    if (proctup == NULL)
        elog(ERROR, "cache lookup failed for function %u", member->object);
    procform = (Form_pg_proc) GETSTRUCT(proctup);

    /*
     * btree comparison procs must be 2-arg procs returning int4.  btree
     * sortsupport procs must take internal and return void.  btree in_range
     * procs must be 5-arg procs returning bool.  hash support proc 1 must be
     * a 1-arg proc returning int4, while proc 2 must be a 2-arg proc
     * returning int8.  Otherwise we don't know.
     */
    if (amoid == BTREE_AM_OID)
    {
        if (member->number == BTORDER_PROC)
        {
            if (procform->pronargs != 2)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("btree comparison procedures must have two arguments")));
            if (procform->prorettype != INT4OID)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("btree comparison procedures must return integer")));

            /*
             * If lefttype/righttype isn't specified, use the proc's input
             * types
             */
            if (!OidIsValid(member->lefttype))
                member->lefttype = procform->proargtypes.values[0];
            if (!OidIsValid(member->righttype))
                member->righttype = procform->proargtypes.values[1];
        }
        else if (member->number == BTSORTSUPPORT_PROC)
        {
            if (procform->pronargs != 1 ||
                procform->proargtypes.values[0] != INTERNALOID)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("btree sort support procedures must accept type \"internal\"")));
            if (procform->prorettype != VOIDOID)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("btree sort support procedures must return void")));

            /*
             * Can't infer lefttype/righttype from proc, so use default rule
             */
        }
        else if (member->number == BTINRANGE_PROC)
        {
            if (procform->pronargs != 5)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("btree in_range procedures must have five arguments")));
            if (procform->prorettype != BOOLOID)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("btree in_range procedures must return boolean")));

            /*
             * If lefttype/righttype isn't specified, use the proc's input
             * types (we look at the test-value and offset arguments)
             */
            if (!OidIsValid(member->lefttype))
                member->lefttype = procform->proargtypes.values[0];
            if (!OidIsValid(member->righttype))
                member->righttype = procform->proargtypes.values[2];
        }
    }
    else if (amoid == HASH_AM_OID)
    {
        if (member->number == HASHSTANDARD_PROC)
        {
            if (procform->pronargs != 1)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("hash procedure 1 must have one argument")));
            if (procform->prorettype != INT4OID)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("hash procedure 1 must return integer")));
        }
        else if (member->number == HASHEXTENDED_PROC)
        {
            if (procform->pronargs != 2)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("hash procedure 2 must have two arguments")));
            if (procform->prorettype != INT8OID)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("hash procedure 2 must return bigint")));
        }

        /*
         * If lefttype/righttype isn't specified, use the proc's input type
         */
        if (!OidIsValid(member->lefttype))
            member->lefttype = procform->proargtypes.values[0];
        if (!OidIsValid(member->righttype))
            member->righttype = procform->proargtypes.values[0];
    }

    /*
     * The default in CREATE OPERATOR CLASS is to use the class' opcintype as
     * lefttype and righttype.  In CREATE or ALTER OPERATOR FAMILY, opcintype
     * isn't available, so make the user specify the types.
     */
    if (!OidIsValid(member->lefttype))
        member->lefttype = typeoid;
    if (!OidIsValid(member->righttype))
        member->righttype = typeoid;

    if (!OidIsValid(member->lefttype) || !OidIsValid(member->righttype))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("associated data types must be specified for index support procedure")));

    ReleaseSysCache(proctup);
}

/*
 * Add a new family member to the appropriate list, after checking for
 * duplicated strategy or proc number.
 */
static void
addFamilyMember(List **list, OpFamilyMember *member, bool isProc)
{
    ListCell   *l;

    foreach(l, *list)
    {
        OpFamilyMember *old = (OpFamilyMember *) lfirst(l);

        if (old->number == member->number &&
            old->lefttype == member->lefttype &&
            old->righttype == member->righttype)
        {
            if (isProc)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("procedure number %d for (%s,%s) appears more than once",
                                member->number,
                                format_type_be(member->lefttype),
                                format_type_be(member->righttype))));
            else
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("operator number %d for (%s,%s) appears more than once",
                                member->number,
                                format_type_be(member->lefttype),
                                format_type_be(member->righttype))));
        }
    }
    *list = lappend(*list, member);
}

/*
 * Dump the operators to pg_amop
 *
 * We also make dependency entries in pg_depend for the opfamily entries.
 * If opclassoid is valid then make an INTERNAL dependency on that opclass,
 * else make an AUTO dependency on the opfamily.
 */
static void
storeOperators(List *opfamilyname, Oid amoid,
               Oid opfamilyoid, Oid opclassoid,
               List *operators, bool isAdd)
{
    Relation    rel;
    Datum       values[Natts_pg_amop];
    bool        nulls[Natts_pg_amop];
    HeapTuple   tup;
    Oid         entryoid;
    ObjectAddress myself,
                referenced;
    ListCell   *l;

    rel = heap_open(AccessMethodOperatorRelationId, RowExclusiveLock);

    foreach(l, operators)
    {
        OpFamilyMember *op = (OpFamilyMember *) lfirst(l);
        char        oppurpose;

        /*
         * If adding to an existing family, check for conflict with an
         * existing pg_amop entry (just to give a nicer error message)
         */
        if (isAdd &&
            SearchSysCacheExists4(AMOPSTRATEGY,
                                  ObjectIdGetDatum(opfamilyoid),
                                  ObjectIdGetDatum(op->lefttype),
                                  ObjectIdGetDatum(op->righttype),
                                  Int16GetDatum(op->number)))
            ereport(ERROR,
                    (errcode(ERRCODE_DUPLICATE_OBJECT),
                     errmsg("operator %d(%s,%s) already exists in operator family \"%s\"",
                            op->number,
                            format_type_be(op->lefttype),
                            format_type_be(op->righttype),
                            NameListToString(opfamilyname))));

        oppurpose = OidIsValid(op->sortfamily) ? AMOP_ORDER : AMOP_SEARCH;

        /* Create the pg_amop entry */
        memset(values, 0, sizeof(values));
        memset(nulls, false, sizeof(nulls));

        values[Anum_pg_amop_amopfamily - 1] = ObjectIdGetDatum(opfamilyoid);
        values[Anum_pg_amop_amoplefttype - 1] = ObjectIdGetDatum(op->lefttype);
        values[Anum_pg_amop_amoprighttype - 1] = ObjectIdGetDatum(op->righttype);
        values[Anum_pg_amop_amopstrategy - 1] = Int16GetDatum(op->number);
        values[Anum_pg_amop_amoppurpose - 1] = CharGetDatum(oppurpose);
        values[Anum_pg_amop_amopopr - 1] = ObjectIdGetDatum(op->object);
        values[Anum_pg_amop_amopmethod - 1] = ObjectIdGetDatum(amoid);
        values[Anum_pg_amop_amopsortfamily - 1] = ObjectIdGetDatum(op->sortfamily);

        tup = heap_form_tuple(rel->rd_att, values, nulls);

        entryoid = CatalogTupleInsert(rel, tup);

        heap_freetuple(tup);

        /* Make its dependencies */
        myself.classId = AccessMethodOperatorRelationId;
        myself.objectId = entryoid;
        myself.objectSubId = 0;

        referenced.classId = OperatorRelationId;
        referenced.objectId = op->object;
        referenced.objectSubId = 0;

        if (OidIsValid(opclassoid))
        {
            /* if contained in an opclass, use a NORMAL dep on operator */
            recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

            /* ... and an INTERNAL dep on the opclass */
            referenced.classId = OperatorClassRelationId;
            referenced.objectId = opclassoid;
            referenced.objectSubId = 0;
            recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
        }
        else
        {
            /* if "loose" in the opfamily, use a AUTO dep on operator */
            recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);

            /* ... and an AUTO dep on the opfamily */
            referenced.classId = OperatorFamilyRelationId;
            referenced.objectId = opfamilyoid;
            referenced.objectSubId = 0;
            recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
        }

        /* A search operator also needs a dep on the referenced opfamily */
        if (OidIsValid(op->sortfamily))
        {
            referenced.classId = OperatorFamilyRelationId;
            referenced.objectId = op->sortfamily;
            referenced.objectSubId = 0;
            recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
        }
        /* Post create hook of this access method operator */
        InvokeObjectPostCreateHook(AccessMethodOperatorRelationId,
                                   entryoid, 0);
    }

    heap_close(rel, RowExclusiveLock);
}

/*
 * Dump the procedures (support routines) to pg_amproc
 *
 * We also make dependency entries in pg_depend for the opfamily entries.
 * If opclassoid is valid then make an INTERNAL dependency on that opclass,
 * else make an AUTO dependency on the opfamily.
 */
static void
storeProcedures(List *opfamilyname, Oid amoid,
                Oid opfamilyoid, Oid opclassoid,
                List *procedures, bool isAdd)
{
    Relation    rel;
    Datum       values[Natts_pg_amproc];
    bool        nulls[Natts_pg_amproc];
    HeapTuple   tup;
    Oid         entryoid;
    ObjectAddress myself,
                referenced;
    ListCell   *l;

    rel = heap_open(AccessMethodProcedureRelationId, RowExclusiveLock);

    foreach(l, procedures)
    {
        OpFamilyMember *proc = (OpFamilyMember *) lfirst(l);

        /*
         * If adding to an existing family, check for conflict with an
         * existing pg_amproc entry (just to give a nicer error message)
         */
        if (isAdd &&
            SearchSysCacheExists4(AMPROCNUM,
                                  ObjectIdGetDatum(opfamilyoid),
                                  ObjectIdGetDatum(proc->lefttype),
                                  ObjectIdGetDatum(proc->righttype),
                                  Int16GetDatum(proc->number)))
            ereport(ERROR,
                    (errcode(ERRCODE_DUPLICATE_OBJECT),
                     errmsg("function %d(%s,%s) already exists in operator family \"%s\"",
                            proc->number,
                            format_type_be(proc->lefttype),
                            format_type_be(proc->righttype),
                            NameListToString(opfamilyname))));

        /* Create the pg_amproc entry */
        memset(values, 0, sizeof(values));
        memset(nulls, false, sizeof(nulls));

        values[Anum_pg_amproc_amprocfamily - 1] = ObjectIdGetDatum(opfamilyoid);
        values[Anum_pg_amproc_amproclefttype - 1] = ObjectIdGetDatum(proc->lefttype);
        values[Anum_pg_amproc_amprocrighttype - 1] = ObjectIdGetDatum(proc->righttype);
        values[Anum_pg_amproc_amprocnum - 1] = Int16GetDatum(proc->number);
        values[Anum_pg_amproc_amproc - 1] = ObjectIdGetDatum(proc->object);

        tup = heap_form_tuple(rel->rd_att, values, nulls);

        entryoid = CatalogTupleInsert(rel, tup);

        heap_freetuple(tup);

        /* Make its dependencies */
        myself.classId = AccessMethodProcedureRelationId;
        myself.objectId = entryoid;
        myself.objectSubId = 0;

        referenced.classId = ProcedureRelationId;
        referenced.objectId = proc->object;
        referenced.objectSubId = 0;

        if (OidIsValid(opclassoid))
        {
            /* if contained in an opclass, use a NORMAL dep on procedure */
            recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

            /* ... and an INTERNAL dep on the opclass */
            referenced.classId = OperatorClassRelationId;
            referenced.objectId = opclassoid;
            referenced.objectSubId = 0;
            recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
        }
        else
        {
            /* if "loose" in the opfamily, use a AUTO dep on procedure */
            recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);

            /* ... and an AUTO dep on the opfamily */
            referenced.classId = OperatorFamilyRelationId;
            referenced.objectId = opfamilyoid;
            referenced.objectSubId = 0;
            recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
        }
        /* Post create hook of access method procedure */
        InvokeObjectPostCreateHook(AccessMethodProcedureRelationId,
                                   entryoid, 0);
    }

    heap_close(rel, RowExclusiveLock);
}


/*
 * Remove operator entries from an opfamily.
 *
 * Note: this is only allowed for "loose" members of an opfamily, hence
 * behavior is always RESTRICT.
 */
static void
dropOperators(List *opfamilyname, Oid amoid, Oid opfamilyoid,
              List *operators)
{
    ListCell   *l;

    foreach(l, operators)
    {
        OpFamilyMember *op = (OpFamilyMember *) lfirst(l);
        Oid         amopid;
        ObjectAddress object;

        amopid = GetSysCacheOid4(AMOPSTRATEGY,
                                 ObjectIdGetDatum(opfamilyoid),
                                 ObjectIdGetDatum(op->lefttype),
                                 ObjectIdGetDatum(op->righttype),
                                 Int16GetDatum(op->number));
        if (!OidIsValid(amopid))
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("operator %d(%s,%s) does not exist in operator family \"%s\"",
                            op->number,
                            format_type_be(op->lefttype),
                            format_type_be(op->righttype),
                            NameListToString(opfamilyname))));

        object.classId = AccessMethodOperatorRelationId;
        object.objectId = amopid;
        object.objectSubId = 0;

        performDeletion(&object, DROP_RESTRICT, 0);
    }
}

/*
 * Remove procedure entries from an opfamily.
 *
 * Note: this is only allowed for "loose" members of an opfamily, hence
 * behavior is always RESTRICT.
 */
static void
dropProcedures(List *opfamilyname, Oid amoid, Oid opfamilyoid,
               List *procedures)
{
    ListCell   *l;

    foreach(l, procedures)
    {
        OpFamilyMember *op = (OpFamilyMember *) lfirst(l);
        Oid         amprocid;
        ObjectAddress object;

        amprocid = GetSysCacheOid4(AMPROCNUM,
                                   ObjectIdGetDatum(opfamilyoid),
                                   ObjectIdGetDatum(op->lefttype),
                                   ObjectIdGetDatum(op->righttype),
                                   Int16GetDatum(op->number));
        if (!OidIsValid(amprocid))
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("function %d(%s,%s) does not exist in operator family \"%s\"",
                            op->number,
                            format_type_be(op->lefttype),
                            format_type_be(op->righttype),
                            NameListToString(opfamilyname))));

        object.classId = AccessMethodProcedureRelationId;
        object.objectId = amprocid;
        object.objectSubId = 0;

        performDeletion(&object, DROP_RESTRICT, 0);
    }
}

/*
 * Deletion subroutines for use by dependency.c.
 */
void
RemoveOpFamilyById(Oid opfamilyOid)
{
    Relation    rel;
    HeapTuple   tup;

    rel = heap_open(OperatorFamilyRelationId, RowExclusiveLock);

    tup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfamilyOid));
    if (!HeapTupleIsValid(tup)) /* should not happen */
        elog(ERROR, "cache lookup failed for opfamily %u", opfamilyOid);

    CatalogTupleDelete(rel, &tup->t_self);

    ReleaseSysCache(tup);

    heap_close(rel, RowExclusiveLock);
}

void
RemoveOpClassById(Oid opclassOid)
{
    Relation    rel;
    HeapTuple   tup;

    rel = heap_open(OperatorClassRelationId, RowExclusiveLock);

    tup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassOid));
    if (!HeapTupleIsValid(tup)) /* should not happen */
        elog(ERROR, "cache lookup failed for opclass %u", opclassOid);

    CatalogTupleDelete(rel, &tup->t_self);

    ReleaseSysCache(tup);

    heap_close(rel, RowExclusiveLock);
}

void
RemoveAmOpEntryById(Oid entryOid)
{
    Relation    rel;
    HeapTuple   tup;
    ScanKeyData skey[1];
    SysScanDesc scan;

    ScanKeyInit(&skey[0],
                ObjectIdAttributeNumber,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(entryOid));

    rel = heap_open(AccessMethodOperatorRelationId, RowExclusiveLock);

    scan = systable_beginscan(rel, AccessMethodOperatorOidIndexId, true,
                              NULL, 1, skey);

    /* we expect exactly one match */
    tup = systable_getnext(scan);
    if (!HeapTupleIsValid(tup))
        elog(ERROR, "could not find tuple for amop entry %u", entryOid);

    CatalogTupleDelete(rel, &tup->t_self);

    systable_endscan(scan);
    heap_close(rel, RowExclusiveLock);
}

void
RemoveAmProcEntryById(Oid entryOid)
{
    Relation    rel;
    HeapTuple   tup;
    ScanKeyData skey[1];
    SysScanDesc scan;

    ScanKeyInit(&skey[0],
                ObjectIdAttributeNumber,
                BTEqualStrategyNumber, F_OIDEQ,
                ObjectIdGetDatum(entryOid));

    rel = heap_open(AccessMethodProcedureRelationId, RowExclusiveLock);

    scan = systable_beginscan(rel, AccessMethodProcedureOidIndexId, true,
                              NULL, 1, skey);

    /* we expect exactly one match */
    tup = systable_getnext(scan);
    if (!HeapTupleIsValid(tup))
        elog(ERROR, "could not find tuple for amproc entry %u", entryOid);

    CatalogTupleDelete(rel, &tup->t_self);

    systable_endscan(scan);
    heap_close(rel, RowExclusiveLock);
}

/*
 * Subroutine for ALTER OPERATOR CLASS SET SCHEMA/RENAME
 *
 * Is there an operator class with the given name and signature already
 * in the given namespace?  If so, raise an appropriate error message.
 */
void
IsThereOpClassInNamespace(const char *opcname, Oid opcmethod,
                          Oid opcnamespace)
{
    /* make sure the new name doesn't exist */
    if (SearchSysCacheExists3(CLAAMNAMENSP,
                              ObjectIdGetDatum(opcmethod),
                              CStringGetDatum(opcname),
                              ObjectIdGetDatum(opcnamespace)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("operator class \"%s\" for access method \"%s\" already exists in schema \"%s\"",
                        opcname,
                        get_am_name(opcmethod),
                        get_namespace_name(opcnamespace))));
}

/*
 * Subroutine for ALTER OPERATOR FAMILY SET SCHEMA/RENAME
 *
 * Is there an operator family with the given name and signature already
 * in the given namespace?  If so, raise an appropriate error message.
 */
void
IsThereOpFamilyInNamespace(const char *opfname, Oid opfmethod,
                           Oid opfnamespace)
{
    /* make sure the new name doesn't exist */
    if (SearchSysCacheExists3(OPFAMILYAMNAMENSP,
                              ObjectIdGetDatum(opfmethod),
                              CStringGetDatum(opfname),
                              ObjectIdGetDatum(opfnamespace)))
        ereport(ERROR,
                (errcode(ERRCODE_DUPLICATE_OBJECT),
                 errmsg("operator family \"%s\" for access method \"%s\" already exists in schema \"%s\"",
                        opfname,
                        get_am_name(opfmethod),
                        get_namespace_name(opfnamespace))));
}