> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-revert-104359-revert-104251-parquet-single.mintlify.site/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 VersionHistory = ({rows = []}) => {
  if (rows.length === 0) {
    return null;
  }
  const headers = ["Version", "Default value", "Comment"];
  const border = "1px solid rgba(128, 128, 128, 0.3)";
  const cell = {
    border,
    padding: "0.25rem 0.5rem",
    textAlign: "start",
    verticalAlign: "top"
  };
  return <details className="not-prose" style={{
    border,
    borderRadius: "0.5rem",
    margin: "0.5rem 0",
    padding: "0.5rem 0.75rem",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <summary style={{
    cursor: "pointer",
    fontWeight: 600,
    opacity: 0.72
  }}>
        Version history
      </summary>
      <table style={{
    borderCollapse: "collapse",
    width: "100%",
    margin: "0.5rem 0 0"
  }}>
        <thead>
          <tr>
            {headers.map(header => <th key={header} style={{
    ...cell,
    fontWeight: 600,
    opacity: 0.72
  }}>
                {header}
              </th>)}
          </tr>
        </thead>
        <tbody>
          {rows.map((row, row_index) => <tr key={row.id ?? row_index}>
              {(row.items ?? []).map((item, item_index) => <td key={item_index} style={{
    ...cell,
    overflowWrap: "anywhere"
  }}>
                  {item?.label}
                </td>)}
            </tr>)}
        </tbody>
      </table>
    </details>;
};

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](/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_apply_final_to_all_joined_tables">
  analyzer\_compatibility\_apply\_final\_to\_all\_joined\_tables
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.8"},{"label": "0"},{"label": "New setting on master (default false = the fixed behavior). The behavior flip itself is recorded under 26.6, and the introduction for backports to older release branches (with default true) under 26.4."}]}, {"id": "row-2","items": [{"label": "26.6"},{"label": "0"},{"label": "Fixed a bug in the analyzer where FINAL on the left-most table of a JOIN was incorrectly applied to the other joined tables as well. previous_value=true so `compatibility` with versions before 26.6 restores the old behavior."}]}, {"id": "row-3","items": [{"label": "26.4"},{"label": "1"},{"label": "New compatibility setting controlling whether FINAL on the left-most table of a JOIN is applied to the other joined tables. Introduced with default true (the old behavior) for backports to versions before 26.6."}]}]} />

Restores the behavior of versions before 26.6, where the `FINAL` modifier specified on the left-most table of a JOIN was incorrectly applied to all other joined tables as well (for engines that support `FINAL`, e.g. `ReplacingMergeTree`). By default `FINAL` applies only to the table it is written on. Enable for compatibility with queries that rely on the old behavior; the recommended fix is to write `FINAL` explicitly on every table that needs it.

Possible values:

* 0 - `FINAL` applies only to the table it is specified on.
* 1 - `FINAL` on the left-most table of a JOIN is applied to all joined tables.

<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`). Aliases defined on subexpressions inside the SELECT list are also considered (for example, in `SELECT uniqExact(a + 1 AS b) FROM t1 JOIN t2 USING (b)` the join is performed by `t1.a + 1 = t2.b`). When the matching alias is defined on a subexpression inside the SELECT list rather than as a top-level alias, parallel replicas are disabled for the query. For queries sent to remote servers (`Distributed` tables, the `remote` table function), such a query is rejected with an exception only when the identifier cannot be resolved on the remote server at all; if the alias shadows a real column of the left table, the remote server joins by that column instead, so the results may differ from local execution.

<h2 id="analyzer_compatibility_multiple_joins_qualify_column_names">
  analyzer\_compatibility\_multiple\_joins\_qualify\_column\_names
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.8"},{"label": "0"},{"label": "New compatibility setting. When enabled, the analyzer mimics the old analyzer's qualified result column names for queries whose FROM clause has two or more JOINs."}]}]} />

When enabled and the `FROM` clause of a query contains two or more `JOIN`s (comma-separated tables count; `ARRAY JOIN` does not), the analyzer names result columns the way the old analyzer's multiple-joins rewrite did:

* columns produced by expanding `*`, `<table>.*` or `COLUMNS('<regexp>')` get names of the form `<alias-or-table>.<column>` (the qualifier is the table expression's alias if it has one, otherwise the table name without the database, otherwise the CTE name; columns of a joined subquery without an alias are left unqualified). Two kinds of column keep their bare name because they belong to the join rather than to a single table expression: a column produced by `ARRAY JOIN`, and a key merged by `JOIN ... USING`. Outer references such as `SELECT ll.arr` or `SELECT ll.k` therefore do not resolve in those two shapes;
* the identifier-list form `COLUMNS(col1, col2)` is not a matcher expansion: each column keeps the name exactly as its identifier was written, so `COLUMNS(x)` produces `x` and `COLUMNS(a.x)` produces `a.x`;
* an unaliased column reference in the `SELECT` list keeps its name exactly as written (e.g. `SELECT a.x` produces a column named `a.x` even when `x` is unambiguous).

This makes outer queries that reference such columns by their qualified names work, for example:

```sql theme={null}
SELECT ll.Date FROM (SELECT * FROM t AS ll LEFT JOIN t1 ON ll.k = t1.k LEFT JOIN t2 ON ll.k = t2.k);
```

Takes effect only when the analyzer is enabled (`enable_analyzer = 1`).

<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.