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Mykyta Protsenko
c87c33f7dd
## Context
GetWorkspaceAgentByInstanceID has a suboptimal plan. Even though it is
designed to fetch a small subset of records, there are no corresponding
indexes and that query results in full table scan:
Query:
```
SELECT id, auth_instance_id FROM workspace_agents
where auth_instance_id='i-013c2b96b6441648a' and deleted=FALSE;
```
Plan:
```
------------------------------------------------------------------------------------------------------------------
Seq Scan on workspace_agents (cost=0.00..222325.48 rows=2 width=36) (actual time=0.012..234.152 rows=4 loops=1)
Filter: ((NOT deleted) AND ((auth_instance_id)::text = 'i-013c2b96b6441648a'::text))
Rows Removed by Filter: 302276
Planning Time: 0.173 ms
Execution Time: 234.169 ms
```
After adding the index, the plan improves drastically.
Updated plan:
```
Bitmap Heap Scan on workspace_agents (cost=4.44..12.32 rows=2 width=36) (actual time=0.019..0.019 rows=0 loops=1)
Recheck Cond: (((auth_instance_id)::text = 'i-013c2b96b6441648a'::text) AND (NOT deleted))
-> Bitmap Index Scan on workspace_agents_auth_instance_id_deleted_idx (cost=0.00..4.44 rows=2 width=0) (actual time=0.013..0.014 rows=0 loops=1)
Index Cond: (((auth_instance_id)::text = 'i-013c2b96b6441648a'::text) AND (deleted = false))
Planning Time: 0.388 ms
Execution Time: 0.044 ms
```
## Changes
* add an index to optimize this query
## Testing
* ran the queries manually against prod and test DBs
* ran `./scripts/develop.sh`, connected to the local PostgreSQL
instance, inspected the indexes to make sure new index is there:
```
Indexes:
"workspace_agents_pkey" PRIMARY KEY, btree (id)
// NEW INDEX CREATED SUCCESSFULLY [comment is mine]
"workspace_agents_auth_instance_id_deleted_idx" btree (auth_instance_id, deleted)
"workspace_agents_auth_token_idx" btree (auth_token)
"workspace_agents_resource_id_idx" btree (resource_id)
```
---------
Signed-off-by: Danny Kopping <danny@coder.com>
Co-authored-by: Danny Kopping <danny@coder.com>
2 lines
75 B
SQL
2 lines
75 B
SQL
DROP INDEX IF EXISTS public.workspace_agents_auth_instance_id_deleted_idx;
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