From e3a23e7d169ec9f64abf57ee5b9f8cb908e77d0e Mon Sep 17 00:00:00 2001
From: Dan Draper <dan@cipherstash.com>
Date: Wed, 6 May 2026 15:26:20 +1000
Subject: [PATCH 1/2] perf: mark eql_v2.like / eql_v2.ilike IMMUTABLE

Without an explicit volatility marker, LANGUAGE sql functions default to
VOLATILE. The planner refuses to inline volatile calls, so
`WHERE eql_v2.like(col, val)` was opaque to a functional bloom_filter
index and silently fell back to a sequential scan.

Both functions are pure over their inputs (their body wraps
`eql_v2.bloom_filter`, which is already IMMUTABLE STRICT PARALLEL SAFE),
so inheriting the same profile is correct.

Adds a regression test that pins provolatile=i for both functions.

Closes #189
---
 src/operators/~~.sql      | 16 ++++++++++++----
 src/operators/~~_test.sql | 31 +++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/src/operators/~~.sql b/src/operators/~~.sql
index 0af0aa887..8ef0ced81 100644
--- a/src/operators/~~.sql
+++ b/src/operators/~~.sql
@@ -14,10 +14,15 @@
 
 
 
+-- IMMUTABLE so the planner inlines the body into the query and a functional
+-- index on `eql_v2.bloom_filter(col)` can match `WHERE eql_v2.like(col, val)`.
 CREATE FUNCTION eql_v2.like(a eql_v2_encrypted, b eql_v2_encrypted)
-RETURNS boolean AS $$
+RETURNS boolean
+LANGUAGE SQL
+IMMUTABLE STRICT PARALLEL SAFE
+AS $$
   SELECT eql_v2.bloom_filter(a) @> eql_v2.bloom_filter(b);
-$$ LANGUAGE SQL;
+$$;
 
 
 --
@@ -25,9 +30,12 @@ $$ LANGUAGE SQL;
 -- Function preserves the SQL semantics
 --
 CREATE FUNCTION eql_v2.ilike(a eql_v2_encrypted, b eql_v2_encrypted)
-RETURNS boolean AS $$
+RETURNS boolean
+LANGUAGE SQL
+IMMUTABLE STRICT PARALLEL SAFE
+AS $$
   SELECT eql_v2.bloom_filter(a) @> eql_v2.bloom_filter(b);
-$$ LANGUAGE SQL;
+$$;
 
 
 
diff --git a/src/operators/~~_test.sql b/src/operators/~~_test.sql
index 6bb054611..1a26a40a0 100644
--- a/src/operators/~~_test.sql
+++ b/src/operators/~~_test.sql
@@ -105,4 +105,35 @@ $$ LANGUAGE plpgsql;
 
 
 
+--
+-- like/ilike must be IMMUTABLE so the planner inlines them into the query
+-- and a functional bloom_filter index can match. See issue #189.
+--
+DO $$
+DECLARE
+    vol "char";
+  BEGIN
+    SELECT provolatile INTO vol
+      FROM pg_proc
+     WHERE pronamespace = 'eql_v2'::regnamespace
+       AND proname = 'like'
+       AND pronargs = 2;
+
+    IF vol <> 'i' THEN
+      RAISE EXCEPTION 'eql_v2.like must be IMMUTABLE (provolatile=i), got %', vol;
+    END IF;
+
+    SELECT provolatile INTO vol
+      FROM pg_proc
+     WHERE pronamespace = 'eql_v2'::regnamespace
+       AND proname = 'ilike'
+       AND pronargs = 2;
+
+    IF vol <> 'i' THEN
+      RAISE EXCEPTION 'eql_v2.ilike must be IMMUTABLE (provolatile=i), got %', vol;
+    END IF;
+  END;
+$$ LANGUAGE plpgsql;
+
+
 SELECT drop_table_with_encrypted();
\ No newline at end of file

From 2e35f0f342ce4da527b9aad65f7a9f7f03bc2a23 Mon Sep 17 00:00:00 2001
From: Dan Draper <dan@cipherstash.com>
Date: Wed, 6 May 2026 16:03:30 +1000
Subject: [PATCH 2/2] style: cargo fmt like_operator_tests

---
 tests/sqlx/tests/like_operator_tests.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tests/sqlx/tests/like_operator_tests.rs b/tests/sqlx/tests/like_operator_tests.rs
index 3e23cd25a..ad0627274 100644
--- a/tests/sqlx/tests/like_operator_tests.rs
+++ b/tests/sqlx/tests/like_operator_tests.rs
@@ -178,7 +178,11 @@ async fn like_and_ilike_are_immutable(pool: PgPool) -> Result<()> {
         .await
         .context("querying pg_proc for like/ilike volatility")?;
 
-    assert_eq!(rows.len(), 2, "expected eql_v2.like and eql_v2.ilike to exist");
+    assert_eq!(
+        rows.len(),
+        2,
+        "expected eql_v2.like and eql_v2.ilike to exist"
+    );
 
     for row in rows {
         let name: String = row.try_get("proname")?;