From 8acb707cc859f1570046919295817e27f0d8b4f6 Mon Sep 17 00:00:00 2001 From: Mats Kindahl Date: Sat, 14 Sep 2024 14:03:35 +0200 Subject: [PATCH] Support extensions wanting to do more advanced analyze To support extensions that want to do more advanced analyzis implementations, this commit adds two function: `analuze_compute_vacattrstats` to compute vacuum attribute stats that can be used to compute the number of target rows to analyze. `read_stream_next_block` which allow an extension to just use the provided analyze stream to sample blocks. --- src/backend/commands/analyze.c | 120 ++++++++++++++------------ src/backend/storage/aio/read_stream.c | 14 +++ src/include/commands/vacuum.h | 2 + src/include/storage/read_stream.h | 2 + 4 files changed, 85 insertions(+), 53 deletions(-) diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index c590a2adc35..8a402ad15c6 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -269,6 +269,72 @@ analyze_rel(Oid relid, RangeVar *relation, pgstat_progress_end_command(); } +/* + * Determine which columns to analyze + * + * Note that system attributes are never analyzed, so we just reject them + * at the lookup stage. We also reject duplicate column mentions. (We + * could alternatively ignore duplicates, but analyzing a column twice + * won't work; we'd end up making a conflicting update in pg_statistic.) + */ +int +analyze_compute_vacattrstats(Relation onerel, List *va_cols, VacAttrStats ***vacattrstats_out) +{ + int tcnt, + i, + attr_cnt; + VacAttrStats **vacattrstats; + + if (va_cols != NIL) + { + Bitmapset *unique_cols = NULL; + ListCell *le; + + vacattrstats = (VacAttrStats **) palloc(list_length(va_cols) * + sizeof(VacAttrStats *)); + tcnt = 0; + foreach(le, va_cols) + { + char *col = strVal(lfirst(le)); + + i = attnameAttNum(onerel, col, false); + if (i == InvalidAttrNumber) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_COLUMN), + errmsg("column \"%s\" of relation \"%s\" does not exist", + col, RelationGetRelationName(onerel)))); + if (bms_is_member(i, unique_cols)) + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_COLUMN), + errmsg("column \"%s\" of relation \"%s\" appears more than once", + col, RelationGetRelationName(onerel)))); + unique_cols = bms_add_member(unique_cols, i); + + vacattrstats[tcnt] = examine_attribute(onerel, i, NULL); + if (vacattrstats[tcnt] != NULL) + tcnt++; + } + attr_cnt = tcnt; + } + else + { + attr_cnt = onerel->rd_att->natts; + vacattrstats = (VacAttrStats **) + palloc(attr_cnt * sizeof(VacAttrStats *)); + tcnt = 0; + for (i = 1; i <= attr_cnt; i++) + { + vacattrstats[tcnt] = examine_attribute(onerel, i, NULL); + if (vacattrstats[tcnt] != NULL) + tcnt++; + } + attr_cnt = tcnt; + } + + *vacattrstats_out = vacattrstats; + return attr_cnt; +} + /* * do_analyze_rel() -- analyze one relation, recursively or not * @@ -353,59 +419,7 @@ do_analyze_rel(Relation onerel, VacuumParams *params, starttime = GetCurrentTimestamp(); } - /* - * Determine which columns to analyze - * - * Note that system attributes are never analyzed, so we just reject them - * at the lookup stage. We also reject duplicate column mentions. (We - * could alternatively ignore duplicates, but analyzing a column twice - * won't work; we'd end up making a conflicting update in pg_statistic.) - */ - if (va_cols != NIL) - { - Bitmapset *unique_cols = NULL; - ListCell *le; - - vacattrstats = (VacAttrStats **) palloc(list_length(va_cols) * - sizeof(VacAttrStats *)); - tcnt = 0; - foreach(le, va_cols) - { - char *col = strVal(lfirst(le)); - - i = attnameAttNum(onerel, col, false); - if (i == InvalidAttrNumber) - ereport(ERROR, - (errcode(ERRCODE_UNDEFINED_COLUMN), - errmsg("column \"%s\" of relation \"%s\" does not exist", - col, RelationGetRelationName(onerel)))); - if (bms_is_member(i, unique_cols)) - ereport(ERROR, - (errcode(ERRCODE_DUPLICATE_COLUMN), - errmsg("column \"%s\" of relation \"%s\" appears more than once", - col, RelationGetRelationName(onerel)))); - unique_cols = bms_add_member(unique_cols, i); - - vacattrstats[tcnt] = examine_attribute(onerel, i, NULL); - if (vacattrstats[tcnt] != NULL) - tcnt++; - } - attr_cnt = tcnt; - } - else - { - attr_cnt = onerel->rd_att->natts; - vacattrstats = (VacAttrStats **) - palloc(attr_cnt * sizeof(VacAttrStats *)); - tcnt = 0; - for (i = 1; i <= attr_cnt; i++) - { - vacattrstats[tcnt] = examine_attribute(onerel, i, NULL); - if (vacattrstats[tcnt] != NULL) - tcnt++; - } - attr_cnt = tcnt; - } + attr_cnt = analyze_compute_vacattrstats(onerel, va_cols, &vacattrstats); /* * Open all indexes of the relation, and see if there are any analyzable diff --git a/src/backend/storage/aio/read_stream.c b/src/backend/storage/aio/read_stream.c index 74b9bae6313..7e25793ea7e 100644 --- a/src/backend/storage/aio/read_stream.c +++ b/src/backend/storage/aio/read_stream.c @@ -804,3 +804,17 @@ read_stream_end(ReadStream *stream) read_stream_reset(stream); pfree(stream); } + +/* + * Transitional support for code that would like to perform a read directly, + * without using the stream. Returns, and skips, the next block number that + * would be read by the stream's look-ahead algorithm, or InvalidBlockNumber + * if the end of the stream is reached. Also reports the strategy that would + * be used to read it. + */ +BlockNumber +read_stream_next_block(ReadStream *stream, BufferAccessStrategy *strategy) +{ + *strategy = stream->ios[0].op.strategy; + return read_stream_get_block(stream, NULL); +} diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index 759f9a87d38..f456734855d 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -378,6 +378,8 @@ extern void parallel_vacuum_main(dsm_segment *seg, shm_toc *toc); extern void analyze_rel(Oid relid, RangeVar *relation, VacuumParams *params, List *va_cols, bool in_outer_xact, BufferAccessStrategy bstrategy); +extern int analyze_compute_vacattrstats(Relation onerel, List *va_cols, + VacAttrStats ***vacattrstats_out); extern bool std_typanalyze(VacAttrStats *stats); /* in utils/misc/sampling.c --- duplicate of declarations in utils/sampling.h */ diff --git a/src/include/storage/read_stream.h b/src/include/storage/read_stream.h index f676d2cc20a..7b9005e87bc 100644 --- a/src/include/storage/read_stream.h +++ b/src/include/storage/read_stream.h @@ -57,6 +57,8 @@ extern ReadStream *read_stream_begin_relation(int flags, void *callback_private_data, size_t per_buffer_data_size); extern Buffer read_stream_next_buffer(ReadStream *stream, void **per_buffer_data); +extern BlockNumber read_stream_next_block(ReadStream *stream, + BufferAccessStrategy *strategy); extern void read_stream_reset(ReadStream *stream); extern void read_stream_end(ReadStream *stream); -- 2.43.0