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Diffstat (limited to 'doc/development/database/query_performance.md')
| -rw-r--r-- | doc/development/database/query_performance.md | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/doc/development/database/query_performance.md b/doc/development/database/query_performance.md index 61fd80338fe..73a6a40f801 100644 --- a/doc/development/database/query_performance.md +++ b/doc/development/database/query_performance.md @@ -15,13 +15,14 @@ When you are optimizing your SQL queries, there are two dimensions to pay attent ## Timing guidelines for queries -| Query Type | Maximum Query Time | Notes | -|----|----|---| -| General queries | `100ms` | This is not a hard limit, but if a query is getting above it, it is important to spend time understanding why it can or cannot be optimized. | -| Queries in a migration | `100ms` | This is different than the total [migration time](../migration_style_guide.md#how-long-a-migration-should-take). | -| Concurrent operations in a migration | `5min` | Concurrent operations do not block the database, but they block the GitLab update. This includes operations such as `add_concurrent_index` and `add_concurrent_foreign_key`. | -| Background migrations | `1s` | | -| Service Ping | `1s` | See the [Service Ping docs](../service_ping/implement.md) for more details. | +| Query Type | Maximum Query Time | Notes | +|-------------------------------------------|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| General queries | `100ms` | This is not a hard limit, but if a query is getting above it, it is important to spend time understanding why it can or cannot be optimized. | +| Queries in a migration | `100ms` | This is different than the total [migration time](../migration_style_guide.md#how-long-a-migration-should-take). | +| Concurrent operations in a migration | `5min` | Concurrent operations do not block the database, but they block the GitLab update. This includes operations such as `add_concurrent_index` and `add_concurrent_foreign_key`. | +| Concurrent operations in a post migration | `20min` | Concurrent operations do not block the database, but they block the GitLab post update process. This includes operations such as `add_concurrent_index` and `add_concurrent_foreign_key`. If index creation exceeds 20 minutes, consider [async index creation](adding_database_indexes.md#create-indexes-asynchronously). | +| Background migrations | `1s` | | +| Service Ping | `1s` | See the [Service Ping docs](../service_ping/implement.md) for more details. | - When analyzing your query's performance, pay attention to if the time you are seeing is on a [cold or warm cache](#cold-and-warm-cache). These guidelines apply for both cache types. - When working with batched queries, change the range and batch size to see how it effects the query timing and caching. |