[DOC-1080][2025.2] Updated defaults for EPCM flags #29478
Conversation
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
✅ Deploy Preview for infallible-bardeen-164bc9 ready!
To edit notification comments on pull requests, go to your Netlify project configuration. |
ddhodge
changed the title
ddhodge
commented
Nov 27, 2025
pkj415
reviewed
Dec 2, 2025
|
|
||
| For new universes running v2025.2 or later, Read Committed is enabled by default when you deploy using yugabyted, YugabyteDB Anywhere, or YugabyteDB Aeon. | ||
|
|
||
| In versions of YugabyteDB prior to v2025.2, or for manually deployed universes, `yb_enable_read_committed_isolation` is `false` (the default), and the Read Committed isolation level of YugabyteDB's transactional layer falls back to the stricter Snapshot isolation. This makes the default isolation level for the YSQL API effectively Snapshot because Read Committed, which is the YSQL API and PostgreSQL syntactic default, maps to Snapshot isolation. |
Contributor
There was a problem hiding this comment.
should we also mention here that upgrading to a version >= 2025.2 will not change the default?
Contributor
There was a problem hiding this comment.
nvm, the "For new universes" part clarifies it
pkj415
reviewed
Dec 2, 2025
|
|
||
| For new YSQL deployments, or when migrating from another system, to enable CBO, add the parameter to [ysql_pg_conf_csv](../../reference/configuration/yb-tserver/#ysql-pg-conf-csv) as follows: | ||
| For new universes running v2025.2 or later, CBO is enabled by default when you deploy using yugabyted, YugabyteDB Anywhere, or YugabyteDB Aeon. | ||
|
|
Contributor
There was a problem hiding this comment.
should we also mention that upgrading to >= 2025.2 will not enable cbo automatically if it was off?
Contributor
There was a problem hiding this comment.
nvm, the "For new universes" part clarifies it
pkj415
reviewed
Dec 2, 2025
| For new universes running v2025.2 or later, parallel append is enabled by default when you deploy using yugabyted, YugabyteDB Anywhere, or YugabyteDB Aeon. | ||
|
|
||
| In addition, when upgrading a deployment to v2025.2 or later, if the universe has the cost-based optimizer enabled (`on`), YugabyteDB will enable parallel append. | ||
|
|
Contributor
There was a problem hiding this comment.
should we also mention that upgrading to a version >= 2025.2 will not automatically enable parallel append if it was off earlier
Contributor
There was a problem hiding this comment.
nvm, the "For new universes" part clarifies it
pkj415
reviewed
Dec 2, 2025
| To enable Read Committed isolation, set the YB-TServer flag [yb_enable_read_committed_isolation](../../../reference/configuration/yb-tserver/#yb-enable-read-committed-isolation) to `true`. By default this flag is `false` and in this case the Read Committed isolation level of the YugabyteDB transactional layer falls back to the stricter Snapshot isolation (in which case `READ COMMITTED` and `READ UNCOMMITTED` of YSQL also in turn use Snapshot isolation). | ||
| Read Committed is supported only if the YB-TServer flag `yb_enable_read_committed_isolation` is set to `true`. | ||
|
|
||
| For new universes running v2025.2 or later, Read Committed is enabled by default when you deploy using yugabyted, YugabyteDB Anywhere, or YugabyteDB Aeon. |
Contributor
There was a problem hiding this comment.
should we also mention here that upgrading to a version >= 2025.2 will not change the default?
Contributor
There was a problem hiding this comment.
nvm, the "For new universes" part clarifies it
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 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.
In 2025.2.0 for new cluster deployed via yugabyted/YBA/Aeon, new flag defaults for:
See also #29514