> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# analyzer_compatibility_* session settings

> ClickHouse session settings in the analyzer_compatibility_* generated group.

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>Type</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>Default</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          Changeable without restart
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

These settings are available in [system.settings](/docs/reference/system-tables/settings) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

<h2 id="analyzer_compatibility_allow_compound_identifiers_in_unflatten_nested">
  analyzer\_compatibility\_allow\_compound\_identifiers\_in\_unflatten\_nested
</h2>

<SettingsInfoBlock type="Bool" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "1"},{"label": "New setting."}]}]} />

Allow to add compound identifiers to nested. This is a compatibility setting because it changes the query result. When disabled, `SELECT a.b.c FROM table ARRAY JOIN a` does not work, and `SELECT a FROM table` does not include `a.b.c` column into `Nested a` result.

<h2 id="analyzer_compatibility_allow_non_aggregate_in_having">
  analyzer\_compatibility\_allow\_non\_aggregate\_in\_having
</h2>

<SettingsInfoBlock type="Bool" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.7"},{"label": "0"},{"label": "New compatibility setting. When enabled, the analyzer mimics the legacy `HAVING`-to-`WHERE` rewrite for non-aggregate AND-conjuncts instead of raising `NOT_AN_AGGREGATE`."}]}]} />

When enabled, the analyzer mimics the legacy behavior of moving non-aggregate AND-conjuncts from `HAVING` to `WHERE` instead of raising `NOT_AN_AGGREGATE`. The standard-compliant rejection is the default; this is a migration aid for queries that were silently accepted by the old analyzer (`enable_analyzer = 0`). Conjuncts containing aggregate, `grouping`, or non-deterministic functions stay in `HAVING`. If any conjunct contains a window function or a stateful function (for example `rowNumberInBlock`), the rewrite is disabled for the whole `HAVING`, matching the legacy `PredicateExpressionsOptimizer` behavior. The setting is also ignored when `GROUP BY` uses `WITH CUBE`, `WITH ROLLUP`, `WITH TOTALS`, or `GROUPING SETS`.

<h2 id="analyzer_compatibility_join_using_top_level_identifier">
  analyzer\_compatibility\_join\_using\_top\_level\_identifier
</h2>

<SettingsInfoBlock type="Bool" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "24.3"},{"label": "0"},{"label": "Force to resolve identifier in JOIN USING from projection"}]}]} />

Force to resolve identifier in JOIN USING from projection (for example, in `SELECT a + 1 AS b FROM t1 JOIN t2 USING (b)` join will be performed by `t1.a + 1 = t2.b`, rather then `t1.b = t2.b`).

<h2 id="analyzer_compatibility_prefer_alias_over_subcolumn">
  analyzer\_compatibility\_prefer\_alias\_over\_subcolumn
</h2>

<SettingsInfoBlock type="Bool" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "0"},{"label": "New compatibility setting"}]}]} />

When a multi-part identifier like `b.id` could refer to either the column `id` of a table aliased `b` or to a Tuple subcolumn `b.id` of some other column, prefer the alias-prefix interpretation (column `id` of `b`). By default the analyzer prefers the subcolumn. Enable to match the old analyzer's resolution.