eliminiate pg catalog functions unless the prefix is typed

Author: emrberk

src/autocomplete/provider.ts

@@ -242,6 +242,11 @@ export function createAutocompleteProvider(
         }
       }
 
+      const partialPrefix =
+        isMidWord && tokensBefore.length > 0
+          ? tokensBefore[tokensBefore.length - 1].image.toLowerCase()
+          : ""
+
       // If parser returned valid next tokens, use grammar-based classification
       if (nextTokenTypes.length > 0) {
         const suggestions = buildSuggestions(
@@ -256,6 +261,7 @@ export function createAutocompleteProvider(
             includeWindowFunctions: suggestWindowFunctions,
             includeTableValuedFunctions: suggestTableValuedFunctions,
             isMidWord,
+            partialPrefix,
           },
         )
         if (suggestTables) {

src/autocomplete/suggestion-builder.ts

@@ -120,6 +120,8 @@ export function buildSuggestions(
     includeWindowFunctions?: boolean
     includeTableValuedFunctions?: boolean
     isMidWord?: boolean
+    /** Lowercased text the user is currently typing (the mid-word token). */
+    partialPrefix?: string
   },
 ): Suggestion[] {
   const suggestions: Suggestion[] = []
@@ -136,6 +138,10 @@ export function buildSuggestions(
   const includeTableValuedFunctions =
     options?.includeTableValuedFunctions ?? false
   const isMidWord = options?.isMidWord ?? false
+  const partialPrefix = options?.partialPrefix ?? ""
+
+  const showPgCatalog = partialPrefix.startsWith("pg")
+  const isPgCatalogName = (name: string): boolean => name.startsWith("pg_")
 
   // Detect join context: when "Join" is a valid next token, join prefix
   // keywords (LEFT, RIGHT, ASOF, etc.) should be suggested as compounds.
@@ -316,6 +322,7 @@ export function buildSuggestions(
     if (isMidWord) {
       const emitFn = (name: string) => {
         if (seenKeywords.has(name.toUpperCase())) return
+        if (isPgCatalogName(name) && !showPgCatalog) return
         suggestions.push({
           label: name,
           kind: SuggestionKind.Function,

src/grammar/functions.ts

@@ -5,11 +5,16 @@
 // and verified against source code in questdb/ and questdb-enterprise/.
 //
 // Categories used for context-aware autocomplete:
-// - scalarFunctions     — single-row functions (FROM functions() type=STANDARD)
-// - aggregateFunctions  — collapse rows (type=GROUP_BY); also valid as windows
-// - windowFunctions     — pure ranking/offset (type=WINDOW, no GROUP_BY overload)
+// - scalarFunctions      — single-row functions (FROM functions() type=STANDARD)
+// - aggregateFunctions   — collapse rows (type=GROUP_BY); also valid as windows
+// - windowFunctions      — pure ranking/offset (type=WINDOW, no GROUP_BY overload)
 // - tableValuedFunctions — return rows (type=CURSOR, or STANDARD that succeeds
-//   in `SELECT * FROM <name>()` — meta pseudo-tables like `materialized_views`)
+//   in `SELECT * FROM <name>()` — meta pseudo-tables like `materialized_views`,
+//   plus PostgreSQL-compat catalog entries like `pg_class` and `pg_catalog.*`.
+//   The pg_-prefixed entries are gated at emission time by the suggestion-
+//   builder: they only surface when the user has typed a "pg" prefix, so the
+//   letter "p" alone doesn't bury real schema results in JOIN positions.
+//   `information_schema.*` is NOT gated — those names are SQL-standard.
 //
 // Removed from earlier flat list: 17 entries absent from QuestDB runtime AND
 // docs (e.g. `array_agg`, `lcase`, `len`, `nvl`, `headers`, `show`,
@@ -181,7 +186,6 @@ export const scalarFunctions: string[] = [
   "sysdate",
   "systimestamp",
   "systimestamp_ns",
-  "table_columns",
   "tan",
   "timestamp_ceil",
   "timestamp_floor",
@@ -210,7 +214,6 @@ export const scalarFunctions: string[] = [
   "typeOf",
   "upper",
   "version",
-  "wal_transactions",
   "week_of_year",
   "within",
   "within_box",
@@ -332,11 +335,13 @@ export const tableValuedFunctions: string[] = [
   "pg_proc",
   "query_activity",
   "reader_pool",
+  "table_columns",
   "table_storage",
   "table_writer_metrics",
   "tables",
   "views",
   "wal_tables",
+  "wal_transactions",
   "writer_pool",
 ]