Skip to content

system-variables: add tidb_paging_size_bytes (internal use) (#23565) #23681

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

Open
ti-chi-bot wants to merge 2 commits into
base: release-8.5
Choose a base branch
from
Open

system-variables: add tidb_paging_size_bytes (internal use) (#23565) #23681

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
a3645ed
system-variables: add tidb_paging_size_bytes (internal use) (#23565)
qiancai Aug 31, 2026
2b3943c
Update system-variables.md
qiancai Sep 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions system-variables.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5402,6 +5402,24 @@ SHOW WARNINGS;
- Range: `[0, 2147483647]`
- This variable controls the iteration of the optimizer's estimation logic. After changing the value of this variable, the estimation logic of the optimizer will change greatly. Currently, `0` is the only valid value. It is not recommended to set it to other values.

### `tidb_paging_size_bytes` <span class="version-mark">New in v9.0.0 and TiDB-X-CLOUD.202603</span>

> **Note:**
>
> This variable is not supported on TiDB Cloud Starter.

- Scope
- TiDB Self-Managed: SESSION | GLOBAL
- TiDB Cloud Essential and Premium: SESSION

@coderabbitai coderabbitai Bot Aug 31, 2026

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

🗄️ Data Integrity & Integration | 🟡 Minor | ⚡ Quick win

🔎 Supported by static analysis

🏁 Script executed:

printf '%s\n' '--- applicable conventions ---'
find /tmp/coderabbit-repo-knowledge/pingcap-docs-9c73f70c -path '*/\*.md' -print | sort
printf '%s\n' '--- target entry ---'
sed -n '5398,5424p' system-variables.md
printf '%s\n' '--- resource-control references ---'
rg -n -C 4 'Essential|non-burst|nonburstable|Resource Control|tidb_paging_size_bytes' \
  --glob '*.md' \
  /tmp/coderabbit-repo-knowledge/pingcap-docs-9c73f70c system-variables.md

Repository: pingcap/docs

Length of output: 5045

🏁 Script executed:

printf '%s\n' '--- applicable conventions ---'
find /tmp/coderabbit-repo-knowledge/pingcap-docs-9c73f70c -type f -name '*.md' -print | sort
printf '%s\n' '--- target entry ---'
sed -n '5398,5424p' system-variables.md
printf '%s\n' '--- resource-control references ---'
rg -n -C 4 'Essential|non-burst|nonburstable|Resource Control|tidb_paging_size_bytes' \
  --glob '*.md' \
  /tmp/coderabbit-repo-knowledge/pingcap-docs-9c73f70c system-variables.md

Repository: pingcap/docs

Length of output: 5310

🏁 Script executed:

printf '%s\n' '--- repository convention ---'
cat /tmp/coderabbit-repo-knowledge/pingcap-docs-9c73f70c/conventions/repo-wide.md
printf '%s\n' '--- resource-control document ---'
resource_doc=$(find . -name 'tidb-resource-control-ru-groups.md' -print -quit)
if [ -n "$resource_doc" ]; then
  rg -n -C 5 'Starter|Essential|Premium|fixed RU|non-burst|burstable|Resource Control' "$resource_doc"
else
  printf '%s\n' 'resource-control document not present in checkout'
fi

Repository: pingcap/docs

Length of output: 7668

Clarify TiDB Cloud Essential availability.

Resource Control is unavailable on TiDB Cloud Essential, but this variable requires Resource Control to take effect. Remove Essential from the scope, or document the internal exception that provides the required Resource Group.

- Persists to cluster: Yes
- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): Yes
- Type: Integer
- Default value: `0`
- Range: `[0, 9223372036854775807]`
- Unit: bytes
- Controls the maximum size, in bytes, of a single paged response in the coprocessor protocol, providing an additional response-size-based pagination mechanism alongside the row-based pagination controlled by [`tidb_max_paging_size`](#tidb_max_paging_size-new-in-v630). The default value of this variable is `0`, which disables byte-based pagination. This feature takes effect only when [resource control](/tidb-resource-control-ru-groups.md) is enabled, and the resource group of the current statement has a fixed RU quota. It allows the PD resource control module to estimate RU consumption based on the amount of data to be scanned and deduct the estimated RUs in advance before the statement is executed. To enable this feature, consider setting the variable to `4194304` (4 MiB).
Comment thread
qiancai marked this conversation as resolved.
- This variable is an internal TiDB variable. It is **not recommended** to modify its value.

### tidb_partition_prune_mode <span class="version-mark">New in v5.1</span>

> **Warning:**
Expand Down