ignore_* session settings

ClickHouse session settings in the ignore_* generated group.

These settings are available in system.settings and are autogenerated from source.

ignore_cold_parts_seconds

Only has an effect in ClickHouse Cloud. Exclude new data parts from SELECT queries until they’re either pre-warmed (see cache_populated_by_fetch) or this many seconds old. Only for Replicated-/SharedMergeTree.

ignore_data_skipping_indexes

Aliases: ignore_data_skipping_indices

Ignores the skipping indexes specified if used by the query.

Consider the following example:

CREATE TABLE data
(
    key Int,
    x Int,
    y Int,
    INDEX x_idx x TYPE minmax GRANULARITY 1,
    INDEX y_idx y TYPE minmax GRANULARITY 1,
    INDEX xy_idx (x,y) TYPE minmax GRANULARITY 1
)
Engine=MergeTree()
ORDER BY key;

INSERT INTO data VALUES (1, 2, 3);

SELECT * FROM data;
SELECT * FROM data SETTINGS ignore_data_skipping_indices=''; -- query will produce CANNOT_PARSE_TEXT error.
SELECT * FROM data SETTINGS ignore_data_skipping_indices='x_idx'; -- Ok.
SELECT * FROM data SETTINGS ignore_data_skipping_indices='na_idx'; -- Ok.

SELECT * FROM data WHERE x = 1 AND y = 1 SETTINGS ignore_data_skipping_indices='xy_idx',force_data_skipping_indices='xy_idx' ; -- query will produce INDEX_NOT_USED error, since xy_idx is explicitly ignored.
SELECT * FROM data WHERE x = 1 AND y = 2 SETTINGS ignore_data_skipping_indices='xy_idx';

The query without ignoring any indexes:

EXPLAIN indexes = 1 SELECT * FROM data WHERE x = 1 AND y = 2;

Expression ((Projection + Before ORDER BY))
  Filter (WHERE)
    ReadFromMergeTree (default.data)
    Indexes:
      PrimaryKey
        Condition: true
        Parts: 1/1
        Granules: 1/1
      Skip
        Name: x_idx
        Description: minmax GRANULARITY 1
        Parts: 0/1
        Granules: 0/1
      Skip
        Name: y_idx
        Description: minmax GRANULARITY 1
        Parts: 0/0
        Granules: 0/0
      Skip
        Name: xy_idx
        Description: minmax GRANULARITY 1
        Parts: 0/0
        Granules: 0/0

Ignoring the xy_idx index:

EXPLAIN indexes = 1 SELECT * FROM data WHERE x = 1 AND y = 2 SETTINGS ignore_data_skipping_indices='xy_idx';

Expression ((Projection + Before ORDER BY))
  Filter (WHERE)
    ReadFromMergeTree (default.data)
    Indexes:
      PrimaryKey
        Condition: true
        Parts: 1/1
        Granules: 1/1
      Skip
        Name: x_idx
        Description: minmax GRANULARITY 1
        Parts: 0/1
        Granules: 0/1
      Skip
        Name: y_idx
        Description: minmax GRANULARITY 1
        Parts: 0/0
        Granules: 0/0

Works with tables in the MergeTree family.

ignore_drop_queries_probability

If enabled, server will ignore all DROP table queries with specified probability (for Memory and JOIN engines it will replace DROP to TRUNCATE). Used for testing purposes

ignore_format_null_for_explain

If enabled, FORMAT Null will be ignored for EXPLAIN queries and default output format will be used instead. When disabled, EXPLAIN queries with FORMAT Null will produce no output (backward compatible behavior).

ignore_materialized_views_with_dropped_target_table

Ignore MVs with dropped target table during pushing to views