Push update to connector (All jdbc)

[vlad-lyutenko]

Description

Introduce push update for jdbc connectors in the same way as delete.
So it's kind of shorthand path, where we catch some specific execution plan.
And only if it's match and it's simple we fire the direct connector call,
omitting global update/merge logic.

In initial version it has some limitations like:

• Push only constant updates, so we not supporting arithmetic expression
• Not supporting Update ALL, where we update all column values.

Supported connectors:

• Ignite
• MariaDB
• MySql
• Oracle
• Postgres
• Redshift
• Singlestore
• SqlServer

Additional context and related issues

Release notes

(x) Release notes are required, with the following suggested text:

Add limited support for UPDATE statement. Only UPDATE with constant assignments and predicates is supported today like UPDATE table SET col1 = 'abc' WHERE col2 = 3

Supported predicates :

• =, !=, >, <, >=, <=, IN, NOT IN

This version has some limitations like:

• Not supporting Update ALL, where we update all column values of table row.
• can not use AND OR in predicates

Supported connectors:

• Ignite
• MariaDB
• MySql
• Oracle
• Postgres
• Redshift
• Singlestore
• SqlServer

[vlad-lyutenko]

Implemented for Postgres to prove that full flow works,
UPDATE nation SET name = 'a' WHERE nationkey = 1; - current query updates nation table

[kokosing]

Approach looks good to me. Add tests like the ones related to io.trino.testing.TestingConnectorBehavior#SUPPORTS_DELETE

[kokosing]

Don't we need assignments here? I think there could be a case where predicate is easy and assignments are complex to be pushed down. Is this handled somewhere else?

[vlad-lyutenko]

As far as I understand this code executed only in PushMergeWriterUpdateIntoConnector rule, where we catch only concrete node plan for simple cases. So in case of complex assignment like Update with Select, we never fall here.
And flow will fail on beginMerge

[martint]

Updates cannot be pushed into a regular table scan. They have fundamentally different semantics -- scans are side-effect-free, while updates have side effects. This is important for retries and transactionality.

[kokosing]

We are already doing this for DELETE.

UPDATE, like DELETE, has side effects but it is idempotent operation (as long query is deterministic). It sounds like a good idea that we should not push down DELETE and UPDATE if they are not deterministic.

[wendigo]

What's the decision here?

[chenjian2664]

I think the update(value is deterministic) can be retry as long as the condition is not involved in the update assignments.

[kokosing]

Updates cannot be pushed into a regular table scan.

@martint notice that we are pushing update into TableUpdateNode, then have dedicated operator that executes the update operation. So there is no table scan here.

[vlad-lyutenko]

Consider expression translation for parsing assignment:

ConnectorExpressionTranslator.ConnectorExpressionTranslation expressionTranslation = ConnectorExpressionTranslator.translateConjuncts(
                    context.getSession(),
                    ((Expression) assigmentNode),
                    context.getSymbolAllocator().getTypes(),
                    plannerContext,
                    typeAnalyzer);

[martint]

Updates cannot be pushed into a regular table scan. They have fundamentally different semantics -- scans are side-effect-free, while updates have side effects. This is important for retries and transactionality.

[chenjian2664]

Very nice job. Only some doubts here, and one more question: I saw the modification in the fte tests, does it mean we can support fte on Update after this merged?

[vlad-lyutenko]

I saw the modification in the fte tests, does it mean we can support fte on Update after this merged?

to be honest didn't get it, can you please describe it more

The engine level changes look good now

[kokosing]

Merged. Thank you @vlad-lyutenko for the change and thank you @martint for code review!

[kokosing]

@vlad-lyutenko Can you please update the PR description and suggest the release notes. Please mention explicitly which connectors are now able to support simple UPDATE statements.