diff options
Diffstat (limited to 'src/include/access/tableam.h')
| -rw-r--r-- | src/include/access/tableam.h | 101 |
1 files changed, 79 insertions, 22 deletions
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index 1cc395317e5..8e583b45cd5 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -20,8 +20,8 @@ #include "access/relscan.h" #include "access/sdir.h" #include "access/xact.h" -#include "commands/vacuum.h" #include "executor/tuptable.h" +#include "storage/read_stream.h" #include "utils/rel.h" #include "utils/snapshot.h" @@ -655,6 +655,50 @@ typedef struct TableAmRoutine struct VacuumParams *params, BufferAccessStrategy bstrategy); + /* + * Prepare to analyze the next block in the read stream. Returns false if + * the stream is exhausted and true otherwise. The scan must have been + * started with SO_TYPE_ANALYZE option. + * + * This routine holds a buffer pin and lock on the heap page. They are + * held until heapam_scan_analyze_next_tuple() returns false. That is + * until all the items of the heap page are analyzed. + */ + + /* + * Prepare to analyze block `blockno` of `scan`. The scan has been started + * with table_beginscan_analyze(). See also + * table_scan_analyze_next_block(). + * + * The callback may acquire resources like locks that are held until + * table_scan_analyze_next_tuple() returns false. It e.g. can make sense + * to hold a lock until all tuples on a block have been analyzed by + * scan_analyze_next_tuple. + * + * The callback can return false if the block is not suitable for + * sampling, e.g. because it's a metapage that could never contain tuples. + * + * XXX: This obviously is primarily suited for block-based AMs. It's not + * clear what a good interface for non block based AMs would be, so there + * isn't one yet. + */ + bool (*scan_analyze_next_block) (TableScanDesc scan, + ReadStream *stream); + + /* + * See table_scan_analyze_next_tuple(). + * + * Not every AM might have a meaningful concept of dead rows, in which + * case it's OK to not increment *deadrows - but note that that may + * influence autovacuum scheduling (see comment for relation_vacuum + * callback). + */ + bool (*scan_analyze_next_tuple) (TableScanDesc scan, + TransactionId OldestXmin, + double *liverows, + double *deadrows, + TupleTableSlot *slot); + /* see table_index_build_range_scan for reference about parameters */ double (*index_build_range_scan) (Relation table_rel, Relation index_rel, @@ -675,12 +719,6 @@ typedef struct TableAmRoutine Snapshot snapshot, struct ValidateIndexState *state); - /* See table_relation_analyze() */ - void (*relation_analyze) (Relation relation, - AcquireSampleRowsFunc *func, - BlockNumber *totalpages, - BufferAccessStrategy bstrategy); - /* ------------------------------------------------------------------------ * Miscellaneous functions. @@ -1683,6 +1721,40 @@ table_relation_vacuum(Relation rel, struct VacuumParams *params, } /* + * Prepare to analyze the next block in the read stream. The scan needs to + * have been started with table_beginscan_analyze(). Note that this routine + * might acquire resources like locks that are held until + * table_scan_analyze_next_tuple() returns false. + * + * Returns false if block is unsuitable for sampling, true otherwise. + */ +static inline bool +table_scan_analyze_next_block(TableScanDesc scan, ReadStream *stream) +{ + return scan->rs_rd->rd_tableam->scan_analyze_next_block(scan, stream); +} + +/* + * Iterate over tuples in the block selected with + * table_scan_analyze_next_block() (which needs to have returned true, and + * this routine may not have returned false for the same block before). If a + * tuple that's suitable for sampling is found, true is returned and a tuple + * is stored in `slot`. + * + * *liverows and *deadrows are incremented according to the encountered + * tuples. + */ +static inline bool +table_scan_analyze_next_tuple(TableScanDesc scan, TransactionId OldestXmin, + double *liverows, double *deadrows, + TupleTableSlot *slot) +{ + return scan->rs_rd->rd_tableam->scan_analyze_next_tuple(scan, OldestXmin, + liverows, deadrows, + slot); +} + +/* * table_index_build_scan - scan the table to find tuples to be indexed * * This is called back from an access-method-specific index build procedure @@ -1787,21 +1859,6 @@ table_index_validate_scan(Relation table_rel, state); } -/* - * table_relation_analyze - fill the infromation for a sampling statistics - * acquisition - * - * The pointer to a function that will collect sample rows from the table - * should be stored to `*func`, plus the estimated size of the table in pages - * should br stored to `*totalpages`. - */ -static inline void -table_relation_analyze(Relation relation, AcquireSampleRowsFunc *func, - BlockNumber *totalpages, BufferAccessStrategy bstrategy) -{ - relation->rd_tableam->relation_analyze(relation, func, - totalpages, bstrategy); -} /* ---------------------------------------------------------------------------- * Miscellaneous functionality |