Function transform_jsonb_arrow_quals

cpp/deeplake_pg/extension_init.cpp:352–434

Transform ->> expressions into @> containment for JSONB index usage

// Transform ->> expressions into @> containment for JSONB index usage
void transform_jsonb_arrow_quals(Node** nodeptr)
{
    if (!nodeptr || !*nodeptr)
        return;
    Node* node = *nodeptr;

    if (IsA(node, BoolExpr)) {
        BoolExpr* b = (BoolExpr*)node;
        ListCell* lc = nullptr;
        foreach (lc, b->args) {
            transform_jsonb_arrow_quals((Node**)&lfirst(lc));
        }
    } else if (IsA(node, OpExpr)) {
        OpExpr* op = (OpExpr*)node;
        char* opname = get_opname(op->opno);

        // Look for: (data -> 'a' -> 'b' ->> 'c') = 'value' or (data ->> 'key') = 'value'
        // Transform to: data @> '{"a": {"b": {"c": "value"}}}'::jsonb
        if (opname && strcmp(opname, "=") == 0 && list_length(op->args) == 2) {
            Node* left = (Node*)linitial(op->args);
            Node* right = (Node*)lsecond(op->args);

            // Check if left side has -> or ->> operators and right is a constant
            if (IsA(left, OpExpr) && IsA(right, Const)) {
                // Extract the full path from nested operators
                std::vector<std::string> path;
                Node* base_col = nullptr;
                extract_jsonb_path(left, path, &base_col);

                if (base_col && !path.empty()) {
                    Oid col_type = exprType(base_col);
                    Const* val = (Const*)right;

                    if (col_type == JSONBOID && !val->constisnull && val->consttype == TEXTOID) {
                        // Build nested JSON
                        char* vs = text_to_cstring(DatumGetTextPP(val->constvalue));
                        std::string json_str = build_nested_json(path, vs);

                        if (!json_str.empty()) {
                            // Convert to JSONB
                            Jsonb* jb =
                                DatumGetJsonbP(DirectFunctionCall1(jsonb_in, CStringGetDatum(json_str.c_str())));

                            // Create JSONB constant
                            Const* jc = makeNode(Const);
                            jc->consttype = JSONBOID;
                            jc->consttypmod = -1;
                            jc->constcollid = InvalidOid;
                            jc->constlen = -1;
                            jc->constvalue = JsonbPGetDatum(jb);
                            jc->constisnull = false;
                            jc->constbyval = false;
                            jc->location = val->location;

                            // Look up @> operator
                            Oid cop = OpernameGetOprid(list_make1(makeString(pstrdup("@>"))), JSONBOID, JSONBOID);
                            if (OidIsValid(cop)) {
                                // Create new @> operator expression