diff options
Diffstat (limited to 'contrib/pgstattuple/pgstatindex.c')
| -rw-r--r-- | contrib/pgstattuple/pgstatindex.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c index d4fc8a0fd60..984ff7c45a0 100644 --- a/contrib/pgstattuple/pgstatindex.c +++ b/contrib/pgstattuple/pgstatindex.c @@ -27,7 +27,9 @@ #include "postgres.h" +#include "access/gin_private.h" #include "access/heapam.h" +#include "access/htup_details.h" #include "access/nbtree.h" #include "catalog/namespace.h" #include "funcapi.h" @@ -39,12 +41,15 @@ extern Datum pgstatindex(PG_FUNCTION_ARGS); extern Datum pg_relpages(PG_FUNCTION_ARGS); +extern Datum pgstatginindex(PG_FUNCTION_ARGS); PG_FUNCTION_INFO_V1(pgstatindex); PG_FUNCTION_INFO_V1(pg_relpages); +PG_FUNCTION_INFO_V1(pgstatginindex); #define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX) #define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID) +#define IS_GIN(r) ((r)->rd_rel->relam == GIN_AM_OID) #define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \ if ( !(FirstOffsetNumber <= (offnum) && \ @@ -79,6 +84,19 @@ typedef struct BTIndexStat uint64 fragments; } BTIndexStat; +/* ------------------------------------------------ + * A structure for a whole GIN index statistics + * used by pgstatginindex(). + * ------------------------------------------------ + */ +typedef struct GinIndexStat +{ + int32 version; + + BlockNumber pending_pages; + int64 pending_tuples; +} GinIndexStat; + /* ------------------------------------------------------ * pgstatindex() * @@ -292,3 +310,79 @@ pg_relpages(PG_FUNCTION_ARGS) PG_RETURN_INT64(relpages); } + +/* ------------------------------------------------------ + * pgstatginindex() + * + * Usage: SELECT * FROM pgstatginindex('ginindex'); + * ------------------------------------------------------ + */ +Datum +pgstatginindex(PG_FUNCTION_ARGS) +{ + Oid relid = PG_GETARG_OID(0); + Relation rel; + Buffer buffer; + Page page; + GinMetaPageData *metadata; + GinIndexStat stats; + HeapTuple tuple; + TupleDesc tupleDesc; + Datum values[3]; + bool nulls[3] = {false, false, false}; + Datum result; + + if (!superuser()) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + (errmsg("must be superuser to use pgstattuple functions")))); + + rel = relation_open(relid, AccessShareLock); + + if (!IS_INDEX(rel) || !IS_GIN(rel)) + elog(ERROR, "relation \"%s\" is not a GIN index", + RelationGetRelationName(rel)); + + /* + * Reject attempts to read non-local temporary relations; we would be + * likely to get wrong data since we have no visibility into the owning + * session's local buffers. + */ + if (RELATION_IS_OTHER_TEMP(rel)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot access temporary indexes of other sessions"))); + + /* + * Read metapage + */ + buffer = ReadBuffer(rel, GIN_METAPAGE_BLKNO); + LockBuffer(buffer, GIN_SHARE); + page = BufferGetPage(buffer); + metadata = GinPageGetMeta(page); + + stats.version = metadata->ginVersion; + stats.pending_pages = metadata->nPendingPages; + stats.pending_tuples = metadata->nPendingHeapTuples; + + UnlockReleaseBuffer(buffer); + relation_close(rel, AccessShareLock); + + /* + * Build a tuple descriptor for our result type + */ + if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE) + elog(ERROR, "return type must be a row type"); + + values[0] = Int32GetDatum(stats.version); + values[1] = UInt32GetDatum(stats.pending_pages); + values[2] = Int64GetDatum(stats.pending_tuples); + + /* + * Build and return the tuple + */ + tuple = heap_form_tuple(tupleDesc, values, nulls); + result = HeapTupleGetDatum(tuple); + + PG_RETURN_DATUM(result); +} |