ydb/yql/essentials/sql, branch main

YQL-20631: Support RECURSIVE WITH CTE on YqlSelect

2026-06-19T13:23:50Z

Implemented a RECURSIVE WITH CTE translation for YqlSelect. It relies on YqlSelf callable. As this callable binds to enclosing YqlSelect, the diagnostic that subquery can't reference an enclosing RECURSIVE WITH CTE was added, it is better, that an existing for pgSQL, where just "table not found" is emitted. The core idea under RECURSIVE handling is that a "not ready" CTE entry is added to a namespace (with a `nullptr` node), so it can be recognized. Checked some interesting test cases and wrote TODOs. commit_hash:65b8646e0615ae070b04822ce7af24245c203bbe

SQL parser + type annotation for Materialize statement

2026-06-18T17:38:07Z

#### SQL Parser and Type Annotation for Materialize Statement ✎ - Added support for the `MATERIALIZE` SQL statement including parser rules and syntax highlighting updates - Implemented type annotation and validation for the `MATERIALIZE` statement with proper error handling - Enhanced SQL query processing to handle `MATERIALIZE` statements in various contexts including subqueries and limited views - Added runtime support for `MATERIALIZE` operations with sort preservation and proper data sink handling - Integrated `MATERIALIZE` into the SQL grammar and updated completion suggestions - Added comprehensive unit tests covering various `MATERIALIZE` scenarios and edge cases Autodescription by Yandex Code Assistant commit_hash:32b04f93ceadf624b4d39fd6512798f9354bfd80

allow removal of custom system prefixes KIKIMR-25775

2026-06-18T16:46:29Z

#### Allow Removal of Custom System Prefixes ✎ - Introduces support for removing custom system column prefixes in addition to default ones during SQL translation - Adds a new configuration option to specify extra system column prefixes that should be stripped from column names - Modifies the column cleanup logic to handle both default system prefixes and user-defined custom prefixes - Includes comprehensive unit tests to verify the behavior with configured prefixes and default cleanup - Ensures backward compatibility by maintaining default system prefix removal when no custom prefixes are configured Autodescription by Yandex Code Assistant commit_hash:b88e8ae9e4905fc2e32299ae104042e8ffa64b57

YQL-20631: Support simple CTEs on YqlSelect

2026-06-18T15:30:10Z

The first iteration on WITH CTE support. Only simple CTEs are supported. Properties: 1. Redefinition is forbidden. 2. Shadowing is supported. 3. Nested WITH CTEs are supported. Following features are not yet implemented: 1. Column names specification. There is an assertion failure at core because of an absent column order when translating it like for the `PgSelect`. 2. `RECURSIVE` is postponed. There a more sophisticated translation with `YqlSelf` callable is required. Also there was a potential defect because of an empty `Id` result not expected. commit_hash:759676d8a9d369f7eedd9b87f79455b2f8a9fcff

Intermediate changes

2026-06-17T14:08:20Z

commit_hash:3682aa4bbce05c002af982ecdc21ea73784a939e

Use Cons! in translator instead of Nth

2026-06-17T10:32:02Z

commit_hash:ec28efb62da755bd372bba274c8eaa0f3f5233f3

YQL-21134: Set UnstableFormat AST flag unconditionally

2026-06-16T13:36:01Z

- Renamed `TAstNodeFlags::IgnoredContent` to `TAstNodeFlags::UnstableFormat` to better reflect its purpose. - Removed the `MarkQueryTextAtomWithIgnoredContent` translation setting. The `UnstableFormat` flag is now unconditionally applied to query text atoms during parsing. - Updated `CheckedFormat` and `ValidateAST` to accept an already parsed AST. Since the flag is now set unconditionally, we can reuse the initial AST for format validation. This avoids re-parsing the original query, reducing redundant AST builds and overall RAM consumption. commit_hash:bba3e6733d3a9c120cf9724a161e603de0cfc038

YQL-20631: Introduce WITH CTE syntax

2026-06-16T11:46:37Z

commit_hash:77f0128cac891f08ce6c8f9a721f66f69032c44e

YQL-20239: Exract pure_ast and move to sql/v1/ide

2026-06-11T12:56:57Z

It is a preparation for a hover LSP method implementation. Query parser and a narrowing visitor are required for the feature, so I extract the logic to a module `pure_ast` from a `complete`. Also modules `complete` and `pure_ast` are moved to `sql/v1/ide/completion` and `sql/v1/ide/pure_ast`. commit_hash:58bed5f2e39bf4779e28468fe7de1e0c4fb2c4c3

YQL-21299: Allow DqEngine and BlockEngine in YqlSelect

2026-06-10T12:13:13Z

I forgot to add them, because they are not enumerated in PRAGMAs table, but handled separately. commit_hash:9ffa2ddbec1d718f9e31c3b2393fea66cefab3dc