Why shardingspere need to load all meta data?

[songxu]

Version

io.shardingsphere.sharding-jdbc-spring-boot-starter:3.0.0

During the initializing, shardingspere will load all table meta in TableMetaDataInitializer.

TableMetaDataInitializer.load(final ShardingRule shardingRule) {
...
result.putAll(loadDefaultTables(shardingRule));
}

It takes much time(almost 2 minutes) to load all meta data.

Question

Why shardingspere need to load all meta data? If I don't load them, what will happen?

Thanks a lot.

[tristaZero]

@songxu
Hi, your issue is duplicate with #1951.
Are you interested in this one? If available, maybe you can fix this problem and give us a pr.

[songxu]

@songxu
Hi, your issue is duplicate with #1951.
Are you interested in this one? If available, maybe you can fix this problem and give us a pr.

Thanks for you reply.
If the meta data isn't loaded at the initializing time, is there any impact?

[tristaZero]

@songxu Hi, recently i am fixing this problem, and this issue occurrs to me. ShardingSphere needs a copy of metadata info to help parsing your SQLs, and checks the metadata consistancy of all the sharding tables. But there is a switch named check.table.metadata.enabled to decide to check it or not. If you don't want to cost too much time when startup, you can config this property. More details, please refer to our document. Thanks.