Add a setting to control what to do with indices during mutations#89335
Merged
Algunenano merged 24 commits intoClickHouse:masterfrom Nov 19, 2025
Merged
Add a setting to control what to do with indices during mutations#89335Algunenano merged 24 commits intoClickHouse:masterfrom
Algunenano merged 24 commits intoClickHouse:masterfrom
Conversation
Contributor
|
Workflow [PR], commit [cd4a414] Summary: ❌
|
clickhouse-gh
bot
added
the
pr-improvement
Algunenano
changed the title
Algunenano
force-pushed
the
rebuild_secondary_index
branch
from
dc27321 to
82a8e7e
Compare
ahmadov
approved these changes
Nov 12, 2025
| extern const MergeTreeSettingsBool allow_suspicious_indices; | ||
| extern const MergeTreeSettingsBool allow_summing_columns_in_partition_or_order_key; | ||
| extern const MergeTreeSettingsBool allow_coalescing_columns_in_partition_or_order_key; | ||
| extern const MergeTreeSettingsAlterColumnSecondaryIndexMode alter_column_secondary_index_mode; |
Member
There was a problem hiding this comment.
[very minor] maybe them after the MergeTreeSettingsBool properties? It makes it easier to read them
Member
Author
There was a problem hiding this comment.
It's shorted by alphabetical order of the setting name (last column) but we can change it
| { | ||
| ASTPtr expr_list = index.expression_list_ast->clone(); | ||
| for (const auto & expr : expr_list->children) | ||
| indices_recalc_expr_list->children.push_back(expr->clone()); |
Member
There was a problem hiding this comment.
[minor] do we need to clone the expr from the cloned list? can we avoid allocation and just move?
Member
Author
There was a problem hiding this comment.
I moved it from the existing code (in getIndicesToRecalculate), I'll have a look to see if we need to clone of we can simply move it (if deep cloned).
Contributor
|
Is the plan to change the default to rebuild? |
Member
Author
|
Yes, this PR changes the default to rebuild |
Member
Author
|
25.11 has been released. Need to change the settings history |
Merged
via the queue into
ClickHouse:master
with commit Nov 19, 2025
2453a19
126 of 132 checks passed
robot-ch-test-poll4
added
the
pr-synced-to-cloud
1 task
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Changelog category (leave one):
Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):
Add a MergeTree setting
alter_column_secondary_index_modeto control what to do with indices during mutations. Possible values: throw, drop, rebuild, and compatibility. Closes #77797Documentation entry for user-facing changes
Details
The setting
alter_column_secondary_index_modecontrols behavior of secondary indices during mutations:throwwill prevent doing ALTER COLUMN MODIFY, UPDATE and DELETE of columns covered by secondary indices or if these mutations will require rewriting the index (DELETES always do).dropwill drop the dependent secondary indices that would otherwise need to be rewritten.rebuildrebuilds any indices affected by the mutation commands.compatibilitykeeps the old behaviour: It throws for ALTER COLUMN MODIFY, and it rebuilds for UPDATE or DELETE.Closes #77797