delete_by_col_eq: optimize with smallvec for 1 row case

Author: Centril

Cargo.lock

@@ -60,6 +60,7 @@ rayon-core.workspace = true
 regex.workspace = true
 rustc-demangle.workspace = true
 rustc-hash.workspace = true
+smallvec.workspace = true
 scopeguard.workspace = true
 sendgrid.workspace = true
 serde.workspace = true

crates/core/Cargo.toml

@@ -3,6 +3,7 @@ use parking_lot::{Mutex, MutexGuard};
 use spacetimedb_lib::{bsatn, ProductValue};
 use std::ops::DerefMut;
 use std::sync::Arc;
+use smallvec::SmallVec;
 
 use crate::database_instance_context::DatabaseInstanceContext;
 use crate::database_logger::{BacktraceProvider, LogLevel, Record};
@@ -162,7 +163,9 @@ impl InstanceEnv {
         let rows_to_delete = stdb
             .iter_by_col_eq(ctx, tx, table_id, col_id, eq_value)?
             .map(|x| RowId(*x.id()))
-            .collect::<Vec<_>>();
+            // `delete_by_field` only cares about 1 element,
+            // so optimize for that.
+            .collect::<SmallVec<[_; 1]>>();
 
         // Delete them and count how many we deleted.
         Ok(stdb.delete(tx, table_id, rows_to_delete))