Waiting for 8.5 – hinting for number of distinct values
Robert Haas wrote, and Tom Lane committed (on 2nd of August) patch which adds interesting capability: Log Message: ----------- Add ALTER TABLE ... ALTER COLUMN ... SET STATISTICS DISTINCT Robert Haas...
View ArticleWhy is my index not being used?
This question (and its variants) show quite often on #postgresql on IRC. People get sequential scans, and are worried that it's slow and bad. So, I hope that this blogpost will shed some light on the...
View ArticleWaiting for 9.2 – filtered info in explain analyze
On 22nd of September, Tom Lane committed patch: Make EXPLAIN ANALYZE report the numbers of rows rejected by filter steps. This provides information about the numbers of tuples that were visited but...
View ArticleWaiting for 9.2 – EXPLAIN TIMING
On 7th of February, Robert Haas committed patch: Sometimes it may be useful to get actual row counts out of EXPLAIN (ANALYZE) without paying the cost of timing every node entry/exit. With this patch,...
View ArticleExplaining the unexplainable – part 5
In previous posts in this series, I talked about how to read EXPLAIN output, and what each line (operation/node) means. Now, in the final post, I will try to explain how it happens that Pg chooses...
View ArticleWaiting for 9.4 – auto_explain: Add logging of trigger execution
On 4th of March, Alvaro Herrera committed patch: auto_explain: Add logging of trigger execution Author: Kyotaro HORIGUCHI Reviewed-by: Jaime Casanova The change is pretty simple, and for most people...
View ArticleWaiting for 8.5 – hinting for number of distinct values
Robert Haas wrote, and Tom Lane committed (on 2nd of August) patch which adds interesting capability: Log Message: ----------- ADD ALTER TABLE ... ALTER COLUMN ... SET STATISTICS DISTINCT Robert Haas...
View ArticleWhy is my index not being used?
This question (and its variants) show quite often on #postgresql on IRC. People get sequential scans, and are worried that it's slow and bad. So, I hope that this blogpost will shed some light on the...
View ArticleWaiting for 9.2 – filtered info in explain analyze
On 22nd of September, Tom Lane committed patch: Make EXPLAIN ANALYZE report the numbers of rows rejected by filter steps. This provides information about the numbers of tuples that were visited but...
View ArticleWaiting for 9.2 – EXPLAIN TIMING
On 7th of February, Robert Haas committed patch: Sometimes it may be useful to get actual row counts out of EXPLAIN (ANALYZE) without paying the cost of timing every node entry/exit. With this patch,...
View ArticleExplaining the unexplainable – part 5
In previous posts in this series, I talked about how to read EXPLAIN output, and what each line (operation/node) means. Now, in the final post, I will try to explain how it happens that Pg chooses...
View ArticleWaiting for 9.4 – auto_explain: Add logging of trigger execution
On 4th of March, Alvaro Herrera committed patch: auto_explain: Add logging of trigger execution Author: Kyotaro HORIGUCHI Reviewed-by: Jaime Casanova The change is pretty simple, and for most people...
View ArticleWaiting for PostgreSQL 13 – Allow vacuum command to process indexes in parallel.
On 20th of January 2020, Amit Kapila committed patch: Allow vacuum command to process indexes in parallel. This feature allows the vacuum to leverage multiple CPUs in order to process indexes. This...
View ArticleWaiting for PostgreSQL 16 – Add grantable MAINTAIN privilege and pg_maintain...
On 14th of December 2022, Jeff Davis committed patch: Add grantable MAINTAIN privilege and pg_maintain role. Allows VACUUM, ANALYZE, REINDEX, REFRESH MATERIALIZED VIEW, CLUSTER, and LOCK TABLE....
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