Verified Commit bd0eb1c6 authored by Tusooa Zhu's avatar Tusooa Zhu Committed by Haelwenn

Make activity search properly use GIN indexes

The original approach to search in GIN indexes is to use
`to_tsvector(text)` in the WHERE clause of the query. According to
postgres docs [pdoc], this method does not make use of the index,
while `to_tsvector(config, text)` does. This commit changed the
query to use the two-argument `to_tsvector()`.

[pdoc]: https://www.postgresql.org/docs/12/textsearch-tables.html

To obtain the search config in use, we make a query to the db first.
The `::regconfig::oid` hack is needed because Postgrex does not support
regconfig type directly [postgrexbug]. I use the conversion from and to
`oid` instead of `text` because I tested in the actual DB and querying
using the conversion via `text` is slow just as the one-argument
`to_tsvector()` variant.

[postgrexbug]: https://github.com/elixir-ecto/postgrex/issues/502

Backport of: !3519

Closes: #2758
parent 53b0dd4e
......@@ -28,6 +28,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
- Mastodon API: Activity Search fallbacks on status fetching after a DB Timeout/Error
- Mastodon API: Fix crash in Streamer related to reblogging
- AdminAPI: List available frontends when `static/frontends` folder is missing
- Make activity search properly use language-aware GIN indexes
## 2.4.0 - 2021-08-08
......
......@@ -65,10 +65,17 @@ defp restrict_public(q) do
end
defp query_with(q, :gin, search_query, :plain) do
%{rows: [[tsc]]} =
Ecto.Adapters.SQL.query!(
Pleroma.Repo,
"select current_setting('default_text_search_config')::regconfig::oid;"
)
from([a, o] in q,
where:
fragment(
"to_tsvector(?->>'content') @@ plainto_tsquery(?)",
"to_tsvector(?::oid::regconfig, ?->>'content') @@ plainto_tsquery(?)",
^tsc,
o.data,
^search_query
)
......@@ -76,10 +83,17 @@ defp query_with(q, :gin, search_query, :plain) do
end
defp query_with(q, :gin, search_query, :websearch) do
%{rows: [[tsc]]} =
Ecto.Adapters.SQL.query!(
Pleroma.Repo,
"select current_setting('default_text_search_config')::regconfig::oid;"
)
from([a, o] in q,
where:
fragment(
"to_tsvector(?->>'content') @@ websearch_to_tsquery(?)",
"to_tsvector(?::oid::regconfig, ?->>'content') @@ websearch_to_tsquery(?)",
^tsc,
o.data,
^search_query
)
......
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