/**
* @fn Datum reorg_get_index_keys(PG_FUNCTION_ARGS)
* @brief Get key definition of the index.
*
* reorg_get_index_keys(index, table)
*
* @param index Oid of target index.
* @param table Oid of table of the index.
* @retval Create index DDL for temp table.
*
* FIXME: this function is named get_index_keys, but actually returns
* an expression for ORDER BY clause. get_order_by() might be a better name.
*/
Datum
reorg_get_index_keys(PG_FUNCTION_ARGS)
{
Oid index = PG_GETARG_OID(0);
Oid table = PG_GETARG_OID(1);
IndexDef stmt;
char *token;
char *next;
StringInfoData str;
Relation indexRel = NULL;
int nattr;
parse_indexdef(&stmt, index, table);
elog(DEBUG2, "indexdef.create = %s", stmt.create);
elog(DEBUG2, "indexdef.index = %s", stmt.index);
elog(DEBUG2, "indexdef.table = %s", stmt.table);
elog(DEBUG2, "indexdef.type = %s", stmt.type);
elog(DEBUG2, "indexdef.columns = %s", stmt.columns);
elog(DEBUG2, "indexdef.options = %s", stmt.options);
/*
* FIXME: this is very unreliable implementation but I don't want to
* re-implement customized versions of pg_get_indexdef_string...
*
* TODO: Support ASC/DESC and NULL FIRST/LAST.
*/
initStringInfo(&str);
for (nattr = 0, next = stmt.columns; next; nattr++)
{
char *opcname;
token = next;
while (isspace((unsigned char) *token))
token++;
next = skip_until(index, next, ',');
opcname = skip_until(index, token, ' ');
if (opcname)
{
/* lookup default operator name from operator class */
Oid opclass;
Oid oprid;
int16 strategy = BTLessStrategyNumber;
Oid opcintype;
Oid opfamily;
HeapTuple tp;
Form_pg_opclass opclassTup;
opclass = OpclassnameGetOpcid(BTREE_AM_OID, opcname);
/* Retrieve operator information. */
tp = SearchSysCache(CLAOID, ObjectIdGetDatum(opclass), 0, 0, 0);
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for opclass %u", opclass);
opclassTup = (Form_pg_opclass) GETSTRUCT(tp);
opfamily = opclassTup->opcfamily;
opcintype = opclassTup->opcintype;
ReleaseSysCache(tp);
if (!OidIsValid(opcintype))
{
if (indexRel == NULL)
indexRel = index_open(index, NoLock);
opcintype = RelationGetDescr(indexRel)->attrs[nattr]->atttypid;
}
oprid = get_opfamily_member(opfamily, opcintype, opcintype, strategy);
if (!OidIsValid(oprid))
elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
strategy, opcintype, opcintype, opfamily);
opcname[-1] = '\0';
appendStringInfo(&str, "%s USING %s", token, get_opname(oprid));
}
else
appendStringInfoString(&str, token);
if (next)
appendStringInfoString(&str, ", ");
}
if (indexRel != NULL)
index_close(indexRel, NoLock);
PG_RETURN_TEXT_P(cstring_to_text(str.data));
}
/*
* Copied from src/backend/commands/indexcmds.c, not exported.
* Resolve possibly-defaulted operator class specification
*/
Oid
GetIndexOpClass(List *opclass, Oid attrType,
char *accessMethodName, Oid accessMethodId)
{
char *schemaname;
char *opcname;
HeapTuple tuple;
Oid opClassId,
opInputType;
/*
* Release 7.0 removed network_ops, timespan_ops, and datetime_ops, so we
* ignore those opclass names so the default *_ops is used. This can be
* removed in some later release. bjm 2000/02/07
*
* Release 7.1 removes lztext_ops, so suppress that too for a while. tgl
* 2000/07/30
*
* Release 7.2 renames timestamp_ops to timestamptz_ops, so suppress that
* too for awhile. I'm starting to think we need a better approach. tgl
* 2000/10/01
*
* Release 8.0 removes bigbox_ops (which was dead code for a long while
* anyway). tgl 2003/11/11
*/
if (list_length(opclass) == 1)
{
char *claname = strVal(linitial(opclass));
if (strcmp(claname, "network_ops") == 0 ||
strcmp(claname, "timespan_ops") == 0 ||
strcmp(claname, "datetime_ops") == 0 ||
strcmp(claname, "lztext_ops") == 0 ||
strcmp(claname, "timestamp_ops") == 0 ||
strcmp(claname, "bigbox_ops") == 0)
opclass = NIL;
}
if (opclass == NIL)
{
/* no operator class specified, so find the default */
opClassId = GetDefaultOpClass(attrType, accessMethodId);
if (!OidIsValid(opClassId))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("data type %s has no default operator class for access method \"%s\"",
format_type_be(attrType), accessMethodName),
errhint("You must specify an operator class for the index or define a default operator class for the data type.")));
return opClassId;
}
/*
* Specific opclass name given, so look up the opclass.
*/
/* deconstruct the name list */
DeconstructQualifiedName(opclass, &schemaname, &opcname);
if (schemaname)
{
/* Look in specific schema only */
Oid namespaceId;
#if PG_VERSION_NUM >= 90300
namespaceId = LookupExplicitNamespace(schemaname, false);
#else
namespaceId = LookupExplicitNamespace(schemaname);
#endif
tuple = SearchSysCache3(CLAAMNAMENSP,
ObjectIdGetDatum(accessMethodId),
PointerGetDatum(opcname),
ObjectIdGetDatum(namespaceId));
}
else
{
/* Unqualified opclass name, so search the search path */
opClassId = OpclassnameGetOpcid(accessMethodId, opcname);
if (!OidIsValid(opClassId))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("operator class \"%s\" does not exist for access method \"%s\"",
opcname, accessMethodName)));
tuple = SearchSysCache1(CLAOID, ObjectIdGetDatum(opClassId));
}
if (!HeapTupleIsValid(tuple))
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("operator class \"%s\" does not exist for access method \"%s\"",
NameListToString(opclass), accessMethodName)));
}
/*
* Verify that the index operator class accepts this datatype. Note we
* will accept binary compatibility.
*/
opClassId = HeapTupleGetOid(tuple);
opInputType = ((Form_pg_opclass) GETSTRUCT(tuple))->opcintype;
if (!IsBinaryCoercible(attrType, opInputType))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("operator class \"%s\" does not accept data type %s",
NameListToString(opclass), format_type_be(attrType))));
ReleaseSysCache(tuple);
return opClassId;
}