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- GreatSQL是MySQL的國產分支版本，使用上與MySQL一致，
事件起因：在測驗一個資料遷移工具時，源端oracle19c資料遷移到目標端mysql8.0，提示遷移目標端 Unknown database 'SBTEST'，報錯如下：
2022-07-29 10:08:19,155 ERROR com.greatsync.connector.jdbc.internal.ComplexJdbcOutputFormat [] - JDBC executeBatch error, retry times = 0
java.sql.BatchUpdateException: Unknown database 'SBTEST'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_312]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:1.8.0_312]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:1.8.0_312]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_312]
at com.mysql.cj.util.Util.handleNewInstance(Util.java:192) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.util.Util.getInstance(Util.java:167) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.util.Util.getInstance(Util.java:174) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.exceptions.SQLError.createBatchUpdateException(SQLError.java:224) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeBatchedInserts(ClientPreparedStatement.java:755) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeBatchInternal(ClientPreparedStatement.java:426) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.StatementImpl.executeBatch(StatementImpl.java:795) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.greatsync.connector.jdbc.statement.FieldNamedPreparedStatementImpl.executeBatch(FieldNamedPreparedStatementImpl.java:77) ~[blob_p-90078b57fb2c51eb5935c045d2e493ef0a7d1524-e9c0e1166eea1bd94ba3d5a23c03b9b3:?]
at com.greatsync.connector.jdbc.internal.executor.TableSimpleStatementExecutor.executeBatch(TableSimpleStatementExecutor.java:63) ~[blob_p-90078b57fb2c51eb5935c045d2e493ef0a7d1524-e9c0e1166eea1bd94ba3d5a23c03b9b3:?]
at com.greatsync.connector.jdbc.internal.executor.TableBufferReducedStatementExecutor.executeBatch(TableBufferReducedStatementExecutor.java:121) ~[blob_p-90078b57fb2c51eb5935c045d2e493ef0a7d1524-e9c0e1166eea1bd94ba3d5a23c03b9b3:?]
at com.greatsync.connector.jdbc.internal.ComplexJdbcOutputFormat.attemptFlush(ComplexJdbcOutputFormat.java:243) ~[blob_p-90078b57fb2c51eb5935c045d2e493ef0a7d1524-e9c0e1166eea1bd94ba3d5a23c03b9b3:?]
at com.greatsync.connector.jdbc.internal.ComplexJdbcOutputFormat.flush(ComplexJdbcOutputFormat.java:210) ~[blob_p-90078b57fb2c51eb5935c045d2e493ef0a7d1524-e9c0e1166eea1bd94ba3d5a23c03b9b3:?]
at com.greatsync.connector.jdbc.internal.ComplexJdbcSinkFunction.lambda$open$0(ComplexJdbcSinkFunction.java:63) ~[blob_p-90078b57fb2c51eb5935c045d2e493ef0a7d1524-e9c0e1166eea1bd94ba3d5a23c03b9b3:?]
at org.apache.flink.streaming.runtime.tasks.StreamTask.invokeProcessingTimeCallback(StreamTask.java:1693) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$null$22(StreamTask.java:1684) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$1.runThrowing(StreamTaskActionExecutor.java:50) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.mailbox.Mail.run(Mail.java:90) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.processMailsNonBlocking(MailboxProcessor.java:353) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.processMail(MailboxProcessor.java:317) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.runMailboxLoop(MailboxProcessor.java:201) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.StreamTask.runMailboxLoop(StreamTask.java:809) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:761) ~[flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.runtime.taskmanager.Task.runWithSystemExitMonitoring(Task.java:958) [flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.runtime.taskmanager.Task.restoreAndInvoke(Task.java:937) [flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:766) [flink-dist_2.11-1.14.4.jar:1.14.4]
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:575) [flink-dist_2.11-1.14.4.jar:1.14.4]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_312]
Caused by: java.sql.SQLSyntaxErrorException: Unknown database 'SBTEST'
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1098) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1046) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeLargeUpdate(ClientPreparedStatement.java:1371) ~[mysql-connector-java-8.0.28.jar:8.0.28]
at com.mysql.cj.jdbc.ClientPreparedStatement.executeBatchedInserts(ClientPreparedStatement.java:716) ~[mysql-connector-java-8.0.28.jar:8.0.28]
... 22 more
于是查看了目標端mysql的databases：
mysql> select @@version,@@default_storage_engine;
+-----------+--------------------------+
| @@version | @@default_storage_engine |
+-----------+--------------------------+
| 8.0.29 | InnoDB |
+-----------+--------------------------+
1 row in set (0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sbtest |
| sys |
+--------------------+
5 rows in set (0.01 sec)
--使用大寫的database name，報錯
mysql> use SBTEST
ERROR 1049 (42000): Unknown database 'SBTEST'
--使用小寫的database name，可以正常訪問
mysql> use sbtest
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
發現目標端是存在sbtest這個庫，但是只能小寫訪問，繼續檢查大小寫敏感配置
mysql> select @@lower_case_table_names;
+--------------------------+
| @@lower_case_table_names |
+--------------------------+
| 0 |
+--------------------------+
1 row in set (0.00 sec)
mysql>
可見目標端的mysql8.0未開啟忽略大寫的配置，oracle的物件名稱默認是大寫，遷移工具遷移時未進行物件名稱轉小寫，導致遷移失敗，程式報錯
這時的想法那手動改下lower_case_table_names不就行了，于是就有了如下的操作：
修改mysql組態檔：
#my.cnf配置中增加如下配置
lower-case-table-names=1
重啟我的mysql8.0 docker容器并查看日志：
root@mysql:~# docker restart mysql8.0.29
mysql8.0.29
root@mysql:~# docker logs -f mysql8.0.29
2022-07-29 02:28:48+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.29-1debian10 started.
2022-07-29 02:28:48+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2022-07-29 02:28:48+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.29-1debian10 started.
2022-07-29T02:28:48.532695-00:00 0 [Warning] [MY-011068] [Server] The syntax 'log_slave_updates' is deprecated and will be removed in a future release. Please use log_replica_updates instead.
2022-07-29T02:28:48.532736-00:00 0 [Warning] [MY-010097] [Server] Insecure configuration for --secure-file-priv: Current value does not restrict location of generated files. Consider setting it to a valid, non-empty path.
2022-07-29T02:28:48.532776-00:00 0 [Warning] [MY-010918] [Server] 'default_authentication_plugin' is deprecated and will be removed in a future release. Please use authentication_policy instead.
2022-07-29T02:28:48.532794-00:00 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.29) starting as process 1
2022-07-29T02:28:48.541090-00:00 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-07-29T02:28:50.875623-00:00 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-07-29T02:28:50.896028-00:00 1 [ERROR] [MY-011087] [Server] Different lower_case_table_names settings for server ('1') and data dictionary ('0').
2022-07-29T02:28:50.896513-00:00 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2022-07-29T02:28:50.897228-00:00 0 [ERROR] [MY-010119] [Server] Aborting
2022-07-29T02:28:51.615910-00:00 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.29) MySQL Community Server - GPL.
2022-07-29 02:28:53+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.29-1debian10 started.
2022-07-29 02:28:53+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2022-07-29 02:28:53+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.29-1debian10 started.
2022-07-29T02:28:54.151877-00:00 0 [Warning] [MY-011068] [Server] The syntax 'log_slave_updates' is deprecated and will be removed in a future release. Please use log_replica_updates instead.
2022-07-29T02:28:54.151918-00:00 0 [Warning] [MY-010097] [Server] Insecure configuration for --secure-file-priv: Current value does not restrict location of generated files. Consider setting it to a valid, non-empty path.
2022-07-29T02:28:54.151954-00:00 0 [Warning] [MY-010918] [Server] 'default_authentication_plugin' is deprecated and will be removed in a future release. Please use authentication_policy instead.
2022-07-29T02:28:54.151972-00:00 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.29) starting as process 1
2022-07-29T02:28:54.401739-00:00 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-07-29T02:28:56.161607-00:00 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-07-29T02:28:56.166187-00:00 1 [ERROR] [MY-011087] [Server] Different lower_case_table_names settings for server ('1') and data dictionary ('0').
2022-07-29T02:28:56.166354-00:00 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2022-07-29T02:28:56.166517-00:00 0 [ERROR] [MY-010119] [Server] Aborting
2022-07-29T02:28:56.800121-00:00 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.29) MySQL Community Server - GPL.
咦，居然重啟失敗并報錯，我記得之前mysql5.7上是可以修改成功的，于是在mysql5.7上復現了一下該修改操作：
mysql> select @@version,@@default_storage_engine;
+------------+--------------------------+
| @@version | @@default_storage_engine |
+------------+--------------------------+
| 5.7.37-log | InnoDB |
+------------+--------------------------+
1 row in set (0.00 sec)
mysql> select @@lower_case_table_names;
+--------------------------+
| @@lower_case_table_names |
+--------------------------+
| 0 |
+--------------------------+
1 row in set (0.00 sec)
組態檔中添加：lower-case-table-names=1后重啟mysql5.7的docker容器
root@mysql:~#docker restart mysql5.7
mysql5.7
-- 查看日志，重啟成功
root@mysql:~#docker logs -f mysql5.7
2022-07-29 04:36:00+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.37-1debian10 started.
2022-07-29 04:36:01+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2022-07-29 04:36:02+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.37-1debian10 started.
2022-07-29T04:36:02.585577-00:00 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2022-07-29T04:36:02.585636-00:00 0 [Warning] Insecure configuration for --secure-file-priv: Current value does not restrict location of generated files. Consider setting it to a valid, non-empty path.
2022-07-29T04:36:02.585657-00:00 0 [Note] mysqld (mysqld 5.7.37-log) starting as process 1 ...
2022-07-29T04:36:02.589953-00:00 0 [Note] InnoDB: PUNCH HOLE support available
2022-07-29T04:36:02.589965-00:00 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2022-07-29T04:36:02.589968-00:00 0 [Note] InnoDB: Uses event mutexes
2022-07-29T04:36:02.589970-00:00 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2022-07-29T04:36:02.589972-00:00 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2022-07-29T04:36:02.589974-00:00 0 [Note] InnoDB: Using Linux native AIO
2022-07-29T04:36:02.590203-00:00 0 [Note] InnoDB: Number of pools: 1
2022-07-29T04:36:02.590301-00:00 0 [Note] InnoDB: Using CPU crc32 instructions
2022-07-29T04:36:02.591501-00:00 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2022-07-29T04:36:02.598983-00:00 0 [Note] InnoDB: Completed initialization of buffer pool
2022-07-29T04:36:02.600436-00:00 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2022-07-29T04:36:02.611754-00:00 0 [Note] InnoDB: Highest supported file format is Barracuda.
2022-07-29T04:36:02.691303-00:00 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2022-07-29T04:36:02.691434-00:00 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2022-07-29T04:36:02.886567-00:00 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2022-07-29T04:36:02.888579-00:00 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2022-07-29T04:36:02.888614-00:00 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2022-07-29T04:36:02.889822-00:00 0 [Note] InnoDB: 5.7.37 started; log sequence number 12662238
2022-07-29T04:36:02.890218-00:00 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2022-07-29T04:36:02.890839-00:00 0 [Note] Plugin 'FEDERATED' is disabled.
2022-07-29T04:36:02.897432-00:00 0 [Note] InnoDB: Buffer pool(s) load completed at 220729 4:36:02
2022-07-29T04:36:03.150414-00:00 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them.
2022-07-29T04:36:03.150468-00:00 0 [Note] Skipping generation of SSL certificates as certificate files are present in data directory.
2022-07-29T04:36:03.150482-00:00 0 [Warning] A deprecated TLS version TLSv1 is enabled. Please use TLSv1.2 or higher.
2022-07-29T04:36:03.150491-00:00 0 [Warning] A deprecated TLS version TLSv1.1 is enabled. Please use TLSv1.2 or higher.
2022-07-29T04:36:03.151831-00:00 0 [Warning] CA certificate ca.pem is self signed.
2022-07-29T04:36:03.151851-00:00 0 [Note] Skipping generation of RSA key pair as key files are present in data directory.
2022-07-29T04:36:03.151929-00:00 0 [Note] Server hostname (bind-address): '*'; port: 3306
2022-07-29T04:36:03.151953-00:00 0 [Note] IPv6 is available.
2022-07-29T04:36:03.151961-00:00 0 [Note] - '::' resolves to '::';
2022-07-29T04:36:03.151968-00:00 0 [Note] Server socket created on IP: '::'.
2022-07-29T04:36:03.206432-00:00 0 [Warning] Insecure configuration for --pid-file: Location '/var/lib/mysql' in the path is accessible to all OS users. Consider choosing a different directory.
2022-07-29T04:36:03.218018-00:00 0 [Note] Failed to start slave threads for channel ''
2022-07-29T04:36:03.234065-00:00 0 [Note] Event Scheduler: Loaded 0 events
2022-07-29T04:36:03.234636-00:00 0 [Note] mysqld: ready for connections.
Version: '5.7.37-log' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)
查看配置生效了：
mysql> root@mysql:~# docker exec -it mysql5.7 bash
root@f9bc50f17027:/# mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.37-log MySQL Community Server (GPL)
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> select @@lower_case_table_names;
+--------------------------+
| @@lower_case_table_names |
+--------------------------+
| 1 |
+--------------------------+
1 row in set (0.00 sec)
確實mysql5.7是支持修改的，mysql8.0不支持修改，于是查了mysql8.0的官網解釋：
https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_lower_case_table_names
-- linux未設定默認是0
The default value of this variable is platform-dependent (see lower_case_file_system). On Linux and other Unix-like systems, the default is 0. On Windows the default value is 1. On macOS, the default value is 2. On Linux (and other Unix-like systems), setting the value to 2 is not supported; the server forces the value to 0 instead.
-- 禁止使用與服務器初始化時使用的設定不同的lower_case_table_names啟動服務器
It is prohibited to start the server with a lower_case_table_names setting that is different from the setting used when the server was initialized. The restriction is necessary because collations used by various data dictionary table fields are determined by the setting defined when the server is initialized, and restarting the server with a different setting would introduce inconsistencies with respect to how identifiers are ordered and compared.
-- 在初始化服務器之前，有必要將lower_case_table_names配置為所需的設定
It is therefore necessary to configure lower_case_table_names to the desired setting before initializing the server. In most cases, this requires configuring lower_case_table_names in a MySQL option file before starting the MySQL server for the first time.
原來需要mysql.0初始化的時候就需要設定好，并且后續不支持修改，于是我又重新用docker部署了一個新的mysql8.0資料庫繼續測驗，
引數說明
- lower_case_table_names=0 表名存盤為給定的大小和比較是區分大小寫的
- lower_case_table_names = 1 表名存盤在磁盤是小寫的，但是比較的時候是不區分大小寫
- lower_case_table_names=2 表名存盤為給定的大小寫但是比較的時候是小寫的
unix,linux下lower_case_table_names默認值為 0 .Windows下默認值是 1 .Mac OS X下默認值是 2
總結
可見我們在使用mysql8.0前需要根據自己的使用場景評估是否要開啟忽略大小寫，如果需要開啟忽略大小寫，初始化前需要把lower-case-table-names=1寫入到my.cnf組態檔中，這樣才不會影響后續的使用，
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