feat: support show database and show tables

[dust1]

Which issue does this PR close?

Closes #66

Rationale for this change

What changes are included in this PR?

In order to satisfy the current three Show statements: show create table, show tables and show database, I modified the Plan part where show create table is located and combined it into a ShowPlan.

Are there any user-facing changes?

For users, two new sql statements are added to find schema and table in ceresDB.

Effect

SHOW TABLES

First, use show tables to view existing tables:
show tables;

Next, use create table sql to create a new table:

CREATE TABLE `hello_show` (`name` string TAG, `value` double NOT NULL, `t` timestamp NOT NULL, TIMESTAMP KEY(t)) ENGINE=Analytic with (enable_ttl='false');

Last view effect
show tables;

SHOW DATABASE

exec show database;

How does this change test

add 2 unit test:

1. test_show_tables_statement_to_plan
2. test_show_database_statement_to_plan

[ShiKaiWi]

Maybe ShowDatabases is a better match to ShowTables compared with ShowDatabase.

[ShiKaiWi]

@dust1 Thanks a lot. You can check our comment reviews if you have time. No need in a hurry. 😜

[dust1]

@ShiKaiWi hello, I have done all modifications, but the weird thing is that my workflow is canceled, can you reboot? I remember that the reviewer can do this

[ShiKaiWi]

@ShiKaiWi hello, I have done all modifications, but the weird thing is that my workflow is canceled, can you reboot? I remember that the reviewer can do this

Sorry for that. Actually, a short timeout (30m) is set by #76 which may lead to a failed ci. And @waynexia will adjust the timeout to 1h.

[waynexia]

@ShiKaiWi hello, I have done all modifications, but the weird thing is that my workflow is canceled, can you reboot? I remember that the reviewer can do this

Sorry for that. Actually, a short timeout (30m) is set by #76 which may lead to a failed ci. And @waynexia will adjust the timeout to 1h.

Sorry for the inconvenience, I've adjust the threshold in #84

[ShiKaiWi]

@dust1 Basically, this PR is good enough for merge expect some issues about naming. For example, it seems there are some ShowDatabse or show_database and maybe it is better to use ShowDatabases and show_databases which matches well with ShowTables and show_tables.

[dust1]

@waynexia hello, I have a strange problem, the github workflow err:

Caused by:
  process didn't exit successfully: `/github/home/target/debug/debug/deps/analytic_engine-f3dcc5bef1a624bd` (signal: 6, SIGABRT: process abort signal)
make: *** [Makefile:36: test-ut] Error 101
Error: Process completed with exit code 2.

I can't find the cause of the problem, and when I run make test-ut locally I get an error because of the env variable was not found.😥

[waynexia]

@waynexia hello, I have a strange problem, the github workflow err:

Caused by:
  process didn't exit successfully: `/github/home/target/debug/debug/deps/analytic_engine-f3dcc5bef1a624bd` (signal: 6, SIGABRT: process abort signal)
make: *** [Makefile:36: test-ut] Error 101
Error: Process completed with exit code 2.

This is caused by #85 . I've rerun the CI (I suppose we need to keep rerun it till success before that issue got solved...😵

I can't find the cause of the problem, and when I run make test-ut locally I get an error because of the env variable was not found.😥

That makefile is for CI. In local env the command is cargo test --workspace

[ShiKaiWi]

@dust1 This pr is basically OK and we can merge it after the two final comments fixed! Thanks again for your contributions.

[dust1]

thank you every reviewer too!😘

[jiacai2050]

LGTM.

[waynexia]

Thanks @dust1 ❤️