grishka/lemmy
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Allow better query plans (#4424)

Browse source 
* Update utils.rs

* Create bind_if_some.rs

* limit connection age

* Delete crates/db_schema/src/utils/bind_if_some.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs

* Update utils.rs
This commit is contained in:
dullbananas 2024-02-12 08:44:29 -07:00 committed by GitHub
parent 300869d397
commit 677d54ae57
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 21 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

24
crates/db_schema/src/utils.rs
View file

@ -25,10 +25,11 @@ use diesel::{
use diesel_async::{
pg::AsyncPgConnection,
pooled_connection::{
deadpool::{Object as PooledConnection, Pool},
deadpool::{Hook, HookError, Object as PooledConnection, Pool},
AsyncDieselConnectionManager,
ManagerConfig,
},
SimpleAsyncConnection,
};
use diesel_migrations::EmbeddedMigrations;
use futures_util::{future::BoxFuture, Future, FutureExt};
@ -46,7 +47,7 @@ use rustls::{
use std::{
ops::{Deref, DerefMut},
sync::Arc,
time::SystemTime,
time::{Duration, SystemTime},
};
use tracing::{error, info};
use url::Url;
@ -335,7 +336,14 @@ fn establish_connection(config: &str) -> BoxFuture<ConnectionResult<AsyncPgConne
error!("Database connection failed: {e}");
}
});
AsyncPgConnection::try_from(client).await
let mut conn = AsyncPgConnection::try_from(client).await?;
// * Change geqo_threshold back to default value if it was changed, so it's higher than the collapse limits
// * Change collapse limits from 8 to 11 so the query planner can find a better table join order for more complicated queries
conn
.batch_execute("SET geqo_threshold=12;SET from_collapse_limit=11;SET join_collapse_limit=11;")
.await
.map_err(ConnectionError::CouldntSetupConfiguration)?;
Ok(conn)
};
fut.boxed()
}
@ -389,6 +397,16 @@ pub async fn build_db_pool() -> Result<ActualDbPool, LemmyError> {
let pool = Pool::builder(manager)
.max_size(SETTINGS.database.pool_size)
.runtime(Runtime::Tokio1)
// Limit connection age to prevent use of prepared statements that have query plans based on very old statistics
.pre_recycle(Hook::sync_fn(|_conn, metrics| {
// Preventing the first recycle can cause an infinite loop when trying to get a new connection from the pool
let conn_was_used = metrics.recycled.is_some();
if metrics.age() > Duration::from_secs(3 * 24 * 60 * 60) && conn_was_used {
Err(HookError::Continue(None))
} else {
Ok(())
}
}))
.build()?;
run_migrations(&db_url)?;