fix: DROP INDEX/TABLE clean up FTS/HNSW indexes and their schema keys

src/barabadb/query/executor.nim

@@ -859,6 +859,15 @@ proc executeQueryImpl(ctx: ExecutionContext, astNode: Node, params: seq[WireValu
     for idxName in ctx.btrees.keys.toSeq():
       if idxName.startsWith(dropName & "."): toDelete.add(idxName)
     for idxName in toDelete: ctx.btrees.del(idxName)
+    # Drop FTS/HNSW engine indexes for this table (in-memory entries)
+    var ftsToDelete: seq[string] = @[]
+    for key in ctx.ftsIndexes.keys.toSeq():
+      if key.startsWith(dropName & "."): ftsToDelete.add(key)
+    for key in ftsToDelete: ctx.ftsIndexes.del(key)
+    var vecToDelete: seq[string] = @[]
+    for key in ctx.vectorIndexes.keys.toSeq():
+      if key.startsWith(dropName & "."): vecToDelete.add(key)
+    for key in vecToDelete: ctx.vectorIndexes.del(key)
     # Remove durable schema entry
     dropTableSchema(ctx, dropName)
     # Remove row data for this table
@@ -869,6 +878,14 @@ proc executeQueryImpl(ctx: ExecutionContext, astNode: Node, params: seq[WireValu
         dataKeys.add(key)
     for key in dataKeys:
       ctx.db.delete(key)
+    # Remove persisted FTS/HNSW index schema keys for this table
+    var engineKeys: seq[string] = @[]
+    for (key, _) in ctx.db.scanAll():
+      if key.startsWith(SchemaFtsIndexPrefix & prefix) or
+         key.startsWith(SchemaVecIndexPrefix & prefix):
+        engineKeys.add(key)
+    for key in engineKeys:
+      ctx.db.delete(key)
     # Drop orphan legacy schema keys that mentioned this table
     var legacyKeys: seq[string] = @[]
     for (key, value) in ctx.db.scanAll():
@@ -1376,6 +1393,35 @@ proc executeQueryImpl(ctx: ExecutionContext, astNode: Node, params: seq[WireValu
     if found:
       ctx.btrees.del(targetKey)
       return okResult(msg="DROP INDEX " & stmt.diName)
+    # FTS/HNSW engine indexes: in-memory maps are keyed by table.col, and a
+    # custom index name only appears in the persisted DDL — match it against
+    # the stored "CREATE INDEX <name> ON" text as well.
+    var ftsKey = ""
+    for key in ctx.ftsIndexes.keys.toSeq():
+      if key == stmt.diName or key.endsWith("." & stmt.diName):
+        ftsKey = key
+        break
+      let (hasDdl, ddl) = ctx.db.get(SchemaFtsIndexPrefix & key)
+      if hasDdl and cast[string](ddl).startsWith("CREATE INDEX " & stmt.diName & " ON "):
+        ftsKey = key
+        break
+    if ftsKey.len > 0:
+      ctx.ftsIndexes.del(ftsKey)
+      ctx.db.delete(SchemaFtsIndexPrefix & ftsKey)
+      return okResult(msg="DROP INDEX " & stmt.diName)
+    var vecKey = ""
+    for key in ctx.vectorIndexes.keys.toSeq():
+      if key == stmt.diName or key.endsWith("." & stmt.diName):
+        vecKey = key
+        break
+      let (hasDdl, ddl) = ctx.db.get(SchemaVecIndexPrefix & key)
+      if hasDdl and cast[string](ddl).startsWith("CREATE INDEX " & stmt.diName & " ON "):
+        vecKey = key
+        break
+    if vecKey.len > 0:
+      ctx.vectorIndexes.del(vecKey)
+      ctx.db.delete(SchemaVecIndexPrefix & vecKey)
+      return okResult(msg="DROP INDEX " & stmt.diName)
     else:
       # Also remove from schema storage
       let idxKey = "_schema:indexes:" & stmt.diName

tests/test_schema_persist.nim

@@ -193,6 +193,109 @@ suite "Schema persistence":
       db2.close()
     removeDir(dir)
 
+  test "DROP INDEX removes FTS index and its schema key (custom name)":
+    let dir = "/tmp/baradb_schema_persist_dropfts"
+    removeDir(dir)
+    block:
+      var db = newLSMTree(dir)
+      var ctx = newExecutionContext(db)
+      check execSql(ctx, "CREATE TABLE docs (id INTEGER PRIMARY KEY, content TEXT)").success
+      check execSql(ctx, "INSERT INTO docs (id, content) VALUES (1, 'quick brown fox')").success
+      check execSql(ctx, "CREATE INDEX docs_fts ON docs (content) USING FTS").success
+      check ctx.ftsIndexes.hasKey("docs.content")
+      # Drop by the custom index name — the in-memory key is table.col
+      let d = execSql(ctx, "DROP INDEX docs_fts")
+      check d.success
+      check "docs.content" notin ctx.ftsIndexes
+      let (found, _) = db.get(SchemaFtsIndexPrefix & "docs.content")
+      check not found
+      db.close()
+    block:
+      var db2 = newLSMTree(dir)
+      var ctx2 = newExecutionContext(db2)
+      check "docs.content" notin ctx2.ftsIndexes  # no ghost rebuild
+      db2.close()
+    removeDir(dir)
+
+  test "DROP INDEX removes FTS index by column key":
+    let dir = "/tmp/baradb_schema_persist_dropfts_col"
+    removeDir(dir)
+    block:
+      var db = newLSMTree(dir)
+      var ctx = newExecutionContext(db)
+      check execSql(ctx, "CREATE TABLE docs (id INTEGER PRIMARY KEY, content TEXT)").success
+      check execSql(ctx, "INSERT INTO docs (id, content) VALUES (1, 'quick brown fox')").success
+      # No custom name — idxName defaults to colKey (docs.content)
+      check execSql(ctx, "CREATE INDEX ON docs (content) USING FTS").success
+      check ctx.ftsIndexes.hasKey("docs.content")
+      # Drop by column name — matches endsWith(".content")
+      let d = execSql(ctx, "DROP INDEX content")
+      check d.success
+      check "docs.content" notin ctx.ftsIndexes
+      let (found, _) = db.get(SchemaFtsIndexPrefix & "docs.content")
+      check not found
+      db.close()
+    block:
+      var db2 = newLSMTree(dir)
+      var ctx2 = newExecutionContext(db2)
+      check "docs.content" notin ctx2.ftsIndexes  # no ghost rebuild
+      db2.close()
+    removeDir(dir)
+
+  test "DROP INDEX removes HNSW index and its schema key":
+    let dir = "/tmp/baradb_schema_persist_drophnsw"
+    removeDir(dir)
+    block:
+      var db = newLSMTree(dir)
+      var ctx = newExecutionContext(db)
+      check execSql(ctx, "CREATE TABLE vecs (id INTEGER PRIMARY KEY, embedding TEXT)").success
+      check execSql(ctx, "INSERT INTO vecs (id, embedding) VALUES (1, '[1.0, 0.0, 0.0]')").success
+      check execSql(ctx, "CREATE INDEX vecs_hnsw ON vecs (embedding) USING HNSW").success
+      check ctx.vectorIndexes.hasKey("vecs.embedding")
+      let d = execSql(ctx, "DROP INDEX vecs_hnsw")
+      check d.success
+      check "vecs.embedding" notin ctx.vectorIndexes
+      let (found, _) = db.get(SchemaVecIndexPrefix & "vecs.embedding")
+      check not found
+      db.close()
+    block:
+      var db2 = newLSMTree(dir)
+      var ctx2 = newExecutionContext(db2)
+      check "vecs.embedding" notin ctx2.vectorIndexes  # no ghost rebuild
+      db2.close()
+    removeDir(dir)
+
+  test "DROP TABLE removes engine indexes for that table":
+    let dir = "/tmp/baradb_schema_persist_droptbl"
+    removeDir(dir)
+    block:
+      var db = newLSMTree(dir)
+      var ctx = newExecutionContext(db)
+      check execSql(ctx, "CREATE TABLE docs (id INTEGER PRIMARY KEY, content TEXT)").success
+      check execSql(ctx, "INSERT INTO docs (id, content) VALUES (1, 'quick brown fox')").success
+      check execSql(ctx, "CREATE INDEX docs_fts ON docs (content) USING FTS").success
+      check execSql(ctx, "CREATE TABLE vecs (id INTEGER PRIMARY KEY, embedding TEXT)").success
+      check execSql(ctx, "INSERT INTO vecs (id, embedding) VALUES (1, '[1.0, 0.0, 0.0]')").success
+      check execSql(ctx, "CREATE INDEX vecs_hnsw ON vecs (embedding) USING HNSW").success
+      check ctx.ftsIndexes.hasKey("docs.content")
+      check ctx.vectorIndexes.hasKey("vecs.embedding")
+      check execSql(ctx, "DROP TABLE docs").success
+      check "docs.content" notin ctx.ftsIndexes
+      check execSql(ctx, "DROP TABLE vecs").success
+      check "vecs.embedding" notin ctx.vectorIndexes
+      let (ftsFound, _) = db.get(SchemaFtsIndexPrefix & "docs.content")
+      check not ftsFound
+      let (vecFound, _) = db.get(SchemaVecIndexPrefix & "vecs.embedding")
+      check not vecFound
+      db.close()
+    block:
+      var db2 = newLSMTree(dir)
+      var ctx2 = newExecutionContext(db2)
+      check "docs.content" notin ctx2.ftsIndexes    # no ghost rebuild
+      check "vecs.embedding" notin ctx2.vectorIndexes
+      db2.close()
+    removeDir(dir)
+
   test "Stable schema key format":
     check tableSchemaKey("users") == "_schema:tables:users"
     check serializeTableDdl(TableDef(