Skip to content

Commit 7e7e517

Browse files
Some more changes
1 parent 65f8d3c commit 7e7e517

File tree

1 file changed

+7
-5
lines changed

1 file changed

+7
-5
lines changed

articles/postgresql/flexible-server/concepts-index-tuning.md

Lines changed: 7 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -38,7 +38,7 @@ The following queries are excluded from that list:
3838
- System-initiated queries. (that is, queries executed by `azuresu` role)
3939
- Queries executed in the context of any system database (`azure_sys`, `template0`, `template1`, and `azure_maintenance`).
4040

41-
The algorithm iterates over the target databases, searching for possible indexes that could improve the performance of analyzed workloads. It also searches for indexes that can be eliminated because they're identified as duplicates or haven't been used for a long period of time.
41+
The algorithm iterates over the target databases, searching for possible indexes that could improve the performance of analyzed workloads. It also searches for indexes that can be eliminated because they're identified as duplicates or not used for a configurable period of time.
4242

4343
### CREATE INDEX recommendations
4444

@@ -61,7 +61,9 @@ Potential recommendations aim to improve the performance of these types of queri
6161
> [!NOTE]
6262
> The only type of indexes the system currently recommends are those of type [B-Tree](https://www.postgresql.org/docs/current/indexes-types.html#INDEXES-TYPES-BTREE).
6363
64-
If a query references one column of a table and that table has no statistics because it was never analyzed (manually using the ANALYZE command or automatically by the autovacuum daemon), then the whole query is skipped, and no indexes are recommended to improve its execution.
64+
If a query references one column of a table and that table has no statistics, then the whole query is skipped and results in no index recommendations to improve its execution.
65+
66+
Analysis required to gather statistics can be triggered manually using the ANALYZE command or automatically by the autovacuum daemon.
6567

6668
`index_tuning.max_indexes_per_table` specifies the number of indexes that can be recommended, excluding any indexes that might already exist on the table for any single table referenced by any number of queries during a tuning session.
6769

@@ -151,7 +153,7 @@ Index tuning in Azure Database for PostgreSQL - Flexible Server has the followin
151153
- In read replicas or when an instance is in read-only mode, index tuning isn't supported.
152154
- It's important to consider the implications of creating recommended indexes on servers with high availability or read replicas, especially when the size of the indexes is estimated to be large.
153155

154-
For more information on index tuning and related articles, see the documentation links provided below.
156+
For more information on index tuning and related articles, see the documentation links provided in [Related content](#related-content).
155157

156158
### Supported regions
157159

@@ -187,11 +189,11 @@ Currently, index tuning doesn't analyze [prepared statements](https://www.postgr
187189

188190
When an Azure Database for PostgreSQL - Flexible Server instance is in read-only modes, such as when the `default_transaction_read_only` parameter is set to `on,` or if the read-only mode is [automatically enabled due to reaching storage capacity](concepts-limits.md#storage), Query Store doesn't capture any data.
189191

190-
Also, index tuning isn't supported currently on read replicas. Any recommendations seen on a read replica, is one that has been produced on the primary replica after having analyzed the workload recorded in it.
192+
Also, index tuning isn't supported currently on read replicas. Any recommendations seen on a read replica, were produced on the primary replica after having analyzed the workload recorded in it.
191193

192194
### Important considerations
193195

194-
If you have [high availability](../../reliability/reliability-postgresql-flexible-server.md) or [read replicas](concepts-read-replicas.md) configured on your server, be aware of the implications associated with producing write-intensive workloads on the primary server when recommended indexes are created by the index tuning feature. Be especially careful when creating indexes whose size is estimated to be large.
196+
If you have [high availability](../../reliability/reliability-postgresql-flexible-server.md) or [read replicas](concepts-read-replicas.md) configured on your server, be aware of the implications associated with producing write-intensive workloads on the primary server when indexes recommended are implemented. Be especially careful when creating indexes whose size is estimated to be significantly large.
195197

196198
## Related content
197199

0 commit comments

Comments
 (0)