tracking: http handler txn support.

[youngsofun]

Summary

make sure:

• without txn
  • old clients can work with new server
  • new clients can work with old server

steps:

• fix clients
  • databend-go [x] refactor session. databend-go#101
  • jdbc [x] fix: remove unused field getKeepServerSessionSecs. databend-jdbc#162
• main feat: http handler txn support. #14802
• update bendsql feat: support transaction. bendsql#356
  • bump version
• add tests use new bendsql
  • @youngsofun https://github.com/datafuselabs/databend/pull/14826， ci: add tests for transaction. #14826
  • @SkyFan2002
• update databend-go
  • fix: update session when query failed. databend-go#103
  • feat: support transaction databend-go#102
• update jdbc feat: support transaction databend-jdbc#168
  • impl Connection::commit(): send 'commit' only when txn_state != null (old server or first query)
• decode and save it as JSON Ast instead of struct

[youngsofun]

• old server: user get error when exec Begin
• old client + new server: Begin/ commit / rollback may success, but txn is not working,
  • client may need to send version or capability to resolve this?

---

for the .session, it is better for clients to decode and save it as JSON Ast instead of struct, and send to server as it is in next query.
if some field is needed by the client, decode and get them separately. 2 advantages

1. not compatibility issue when new field is added to the session state
2. some field is that client do not care can be ignored when decoding to struct.

I will try this later

[hantmac]

• old server: user get error when exec Begin

• old client + new server: Begin/ commit / rollback may success, but txn is not working,

  • client may need to send version or capability to resolve this?

for the .session, it is better for clients to decode and save it as JSON Ast instead of struct, and send to server as it is in next query. if some field is needed by the client, decode and get them separately. 2 advantages

1. not compatibility issue when new field is added to the session state
2. some field is that client do not care can be ignored when decoding to struct.

I will try this later

@youngsofun Which API need client call when Begin, commit, and rollback? Or use specified SQL ?

[youngsofun]

@hantmac use specified SQL