LadyForest commented on code in PR #167:
URL: https://github.com/apache/flink-table-store/pull/167#discussion_r902611941
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docs/content/docs/development/write-table.md:
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@@ -192,3 +192,95 @@ There are three main places in the Table Store's sink
writer that take up memory
- The memory consumed by compaction for reading files, it can be adjusted by
the
`num-sorted-run.compaction-trigger` option to change the maximum number of
files to be merged.
- The memory consumed by writing file, which is not adjustable.
+
+
+## Scale Bucket
+
+Since the LSM trees are built against each bucket, the number of total buckets
dramatically influences the performance.
+Table Store allows users to tune bucket numbers by `ALTER TABLE` command and
reorganize data layout by `INSERT OVERWRITE`
+without recreating the table/partition. When executing overwrite jobs, the
framework will automatically scan the data with
+the bucket number recorded in manifest file and hash the record according to
the current bucket numbers.
+
+#### Rescale Overwrite
+```sql
+-- scale number of total buckets
+ALTER TABLE table_dentifier SET ('bucket' = '...')
+
+-- reorganize data layout of table/partition
+INSERT OVERWRITE table_identifier [PARTITION (part_spec)]
+SELECT ...
+FROM table_identifier
+[WHERE part_spec]
+```
+
+Please beware that
+- `ALTER TABLE` only modifies the table's metadata and will **NOT** reorganize
or reformat existing data.
+ Reorganize exiting data must be achieved by `INSERT OVERWRITE`.
+- Scale bucket number does not influence the read and running write jobs.
+- Once the bucket number is changed, any new `INSERT INTO` jobs without
reorganize table/partition
Review Comment:
> You can say that reading is perfectly fine as long as this partition does
not continue to write data.
Well, I think the reading task is always fine because the read scan always
uses the manifest's bucket number?
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