Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

opt: prune unnecessary check columns #56007

Merged
merged 1 commit into from
Oct 28, 2020
Merged

opt: prune unnecessary check columns #56007

merged 1 commit into from
Oct 28, 2020

Commits on Oct 27, 2020

  1. opt: prune unnecessary check columns 

    This commit updates the optimizer to prune synthesized `CHECK`
constraint columns for `UPDATES` when columns referenced in the
constraints are not updated. This may also allow the optimizer to no
longer fetch those referenced columns.

This should provide a performance benefit for `UDPATE`s to tables with
check constraints. Notably, tables that have been given many column
families (in order to reduce contention) should see a significant
reduction in contention for `UPDATE`s that mutate a subset of column
families.

Informs cockroachdb#51526

Release note (performance improvement): Previously, all `CHECK`
constraints defined on a table would be tested for every `UPDATE` to the
table. Now, a check constraint will not be tested for validity when the
values of columns it references are not being updated. The referenced
columns are no longer fetchecd in cases where they were only fetched to
test `CHECK` constraints.
    @mgartner
    mgartner committed Oct 27, 2020
    Configuration menu
    Copy the full SHA
    d9a906e View commit details
    Browse the repository at this point in the history