From 9469d8ec4977b18b1a0f7deab01d1305dc9987bb Mon Sep 17 00:00:00 2001 From: qiancai Date: Mon, 3 Mar 2025 10:25:21 +0800 Subject: [PATCH] DB2 -> Db2 --- faq/migration-tidb-faq.md | 4 ++-- optimizer-fix-controls.md | 2 +- releases/release-8.4.0.md | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/faq/migration-tidb-faq.md b/faq/migration-tidb-faq.md index df3bc71a5c9dd..07a3fb32492fc 100644 --- a/faq/migration-tidb-faq.md +++ b/faq/migration-tidb-faq.md @@ -81,9 +81,9 @@ You can use the following methods to export the data in TiDB: - Export data using mysqldump and the `WHERE` clause. - Use the MySQL client to export the results of `select` to a file. -### How to migrate from DB2 or Oracle to TiDB? +### How to migrate from Db2 or Oracle to TiDB? -To migrate all the data or migrate incrementally from DB2 or Oracle to TiDB, see the following solution: +To migrate all the data or migrate incrementally from Db2 or Oracle to TiDB, see the following solution: - Use the official migration tool of Oracle, such as OGG, Gateway, CDC (Change Data Capture). - Develop a program for importing and exporting data. diff --git a/optimizer-fix-controls.md b/optimizer-fix-controls.md index 0d0b905a07cbe..8bed386a38cae 100644 --- a/optimizer-fix-controls.md +++ b/optimizer-fix-controls.md @@ -88,7 +88,7 @@ SET SESSION tidb_opt_fix_control = '44262:ON,44389:ON'; - Default value: `ON` - Possible values: `ON`, `OFF` - Due to challenges in accurately estimating the number of qualified rows for each plan step in a query plan, the optimizer might estimate a smaller value for `estRows`. This variable controls whether to limit the minimum value of `estRows`. -- `ON`: limits the minimum value of `estRows` to 1, which is the new behavior introduced in v8.4.0 and is consistent with other databases, such as Oracle and DB2. +- `ON`: limits the minimum value of `estRows` to 1, which is the new behavior introduced in v8.4.0 and is consistent with other databases, such as Oracle and Db2. - `OFF`: disables the minimum row estimate limit, which maintains the behavior consistent with versions before v8.4.0. In this case, `estRows` might be zero. ### [`52592`](https://github.com/pingcap/tidb/issues/52592) New in v8.4.0 diff --git a/releases/release-8.4.0.md b/releases/release-8.4.0.md index b6a5e8ad64a91..ae5c66d5f8b7e 100644 --- a/releases/release-8.4.0.md +++ b/releases/release-8.4.0.md @@ -371,7 +371,7 @@ The following features are planned for deprecation in future versions: - Optimize the efficiency of constructing BatchCop tasks when scanning a large amount of data [#55915](https://github.com/pingcap/tidb/issues/55915) [#55413](https://github.com/pingcap/tidb/issues/55413) @[wshwsh12](https://github.com/wshwsh12) - Optimize the transaction's buffer to reduce write latency in transactions and TiDB CPU usage [#55287](https://github.com/pingcap/tidb/issues/55287) @[you06](https://github.com/you06) - Optimize the execution performance of DML statements when the system variable `tidb_dml_type` is set to `"bulk"` [#50215](https://github.com/pingcap/tidb/issues/50215) @[ekexium](https://github.com/ekexium) - - Support using [Optimizer Fix Control 47400](/optimizer-fix-controls.md#47400-new-in-v840) to control whether the optimizer limits the minimum value estimated for `estRows` to `1`, which is consistent with databases such as Oracle and DB2 [#47400](https://github.com/pingcap/tidb/issues/47400) @[terry1purcell](https://github.com/terry1purcell) + - Support using [Optimizer Fix Control 47400](/optimizer-fix-controls.md#47400-new-in-v840) to control whether the optimizer limits the minimum value estimated for `estRows` to `1`, which is consistent with databases such as Oracle and Db2 [#47400](https://github.com/pingcap/tidb/issues/47400) @[terry1purcell](https://github.com/terry1purcell) - Add write control to the [`mysql.tidb_runaway_queries`](/mysql-schema/mysql-schema.md#system-tables-related-to-runaway-queries) log table to reduce overhead caused by a large number of concurrent writes [#54434](https://github.com/pingcap/tidb/issues/54434) @[HuSharp](https://github.com/HuSharp) - Support Index Join by default when the inner table has `Selection`, `Projection`, or `Aggregation` operators on it [#47233](https://github.com/pingcap/tidb/issues/47233) @[winoros](https://github.com/winoros) - Reduce the number of column details fetched from TiKV for `DELETE` operations in certain scenarios, lowering the resource overhead of these operations [#38911](https://github.com/pingcap/tidb/issues/38911) @[winoros](https://github.com/winoros)