schema: fetch all results of internal sql would cause OOM

[fzhedu]

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)
   HandleUpdateStats load all previous stats, it would occupy too much memory so that to cause OOM. In fact, we can process the updates chunk by chunk.

2. What did you expect to see? (Required)
   normally occupy memory

3. What did you see instead (Required)
   OOM

4. What is your TiDB version? (Required)
   v4.0.X, master

[sre-bot]

Integrity check：
RCA symptom affect_version fix_version fields are empty
@fzhedu
Please comment /info to get template

[ti-srebot]

Please edit this comment to complete the following information

Bug

1. Root Cause Analysis (RCA)
   HandleUpdateStats load all previous stats, it would occupy too much memory so that to cause OOM. In fact, we can process the updates chunk by chunk.

2. Symptom
   OOM

3. Minimal steps to reproduce the bug (optional)

4. Solution (optional)

5. W/A (Workaround)
   disable feedback

6. Affected versions
   [v4.0.0:v4.0.5]

7. Fixed versions
   v4.0.6

[seiya-annie]

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)
   HandleUpdateStats load all previous stats, it would occupy too much memory so that to cause OOM. In fact, we can process the updates chunk by chunk.

2. What did you expect to see? (Required)
   normally occupy memory

3. What did you see instead (Required)
   OOM

4. What is your TiDB version? (Required)
   v4.0.X, master

[seiya-annie]

Please edit this comment to complete the following information

Not a bug

1. Remove the 'type/bug' label
2. Add notes to indicate why it is not a bug

Duplicate bug

1. Add the 'type/duplicate' label
2. Add the link to the original bug

Bug

Note: Make Sure that 'component', and 'severity' labels are added
Example for how to fill out the template: #20100

1. Root Cause Analysis (RCA)

HandleUpdateStats load all previous stats, it would occupy too much memory so that to cause OOM. In fact, we can process the updates chunk by chunk.

2. Symptom

OOM

3. All Trigger Conditions

HandleUpdateStats load all previous stats, it would occupy too much memory so that to cause OOM. In fact, we can process the updates chunk by chunk.

4. Workaround (optional)

disable feedback

5. Affected versions

[v4.0.0:v4.0.5]

6. Fixed versions

v4.0.6