Add oracle, redshift, postgresql jdbc fetch size

[vlad-lyutenko]

trino specific heuristic is applied if empty or zero

Description

Additional context and related issues

Release notes

( ) This is not user-visible or is docs only, and no release notes are required.
( ) Release notes are required. Please propose a release note for me.
(x) Release notes are required, with the following suggested text:

# Oracle, Redshift, PostgreSql
* Allow customising fetch size using `oracle.fetch-size`, `redshift.fetch-size` , `postgresql.fetch-size` respectively for each connector. 

[Praveen2112]

How about having a commit for each connector ?

[vlad-lyutenko]

But not setting the value is not equivalent to setting it as 0 right ?

For Oracle :

public final void setFetchSize(int rows) throws SQLException {
        Monitor.CloseableLock lock = this.connection.acquireCloseableLock();

        try {
            this.ensureOpen();
            this.setPrefetchInternal(rows, false, true);
            this.isFetchSizeSet = rows != 0;
            this.autoTuneRowPrefetch = false;

For redshift:

public void setFetchSize(int rows) throws SQLException {
        if (RedshiftLogger.isEnable()) {
            this.connection.getLogger().logFunction(true, new Object[]{rows});
        }

        this.checkClosed();
        if (rows < 0) {
            throw new RedshiftException(GT.tr("Fetch size must be a value greater to or equal to 0.", new Object[0]), RedshiftState.INVALID_PARAMETER_VALUE);
        } else {
            this.fetchSize = rows;

and fetchsize:
this.fetchSize = 0;

for postgress:
DEFAULT_ROW_FETCH_SIZE("defaultRowFetchSize", "0", "Positive number of rows that should be fetched from the database when more rows are needed for ResultSet by each fetch iteration"),

So set 0 is equal to not set.

And latter in the code there is check:

  if (new_value == 0) {
                new_value = this.connection.getDefaultRowPrefetch();
            }

So if initial value is 0 (or not set), then DefaultRowPrefetch is applied.

[vlad-lyutenko]

But the default value could change it is not equivalent to 10 or 0 or any number right ?

As far as I understood connector's code, setting fetch size to 0 or not setting it at all, means for connectors - use some internal default value.

[ebyhr]

@vlad-lyutenko We didn't agree with this new property on #16269 and merged #16644 instead. Could you explain more detailed context in the PR description?

[vlad-lyutenko]

@vlad-lyutenko We didn't agree with this new property on #16269 and merged #16644 instead. Could you explain more detailed context in the PR description?

Yep, but our heuristic formula is not perfect (I mean doesn't cover all corner cases), if user knows better his data layout and query type, maybe it's worth to give him ability to set explicitly fetch size, until we tune our heuristic formula to the perfect state.

[Praveen2112]

% comments

[Praveen2112]

/test-with-secrets sha=4be2983e71641333581c42607670e5266bbffe53

[github-actions]

The CI workflow run with tests that require additional secrets finished as failure: https://github.com/trinodb/trino/actions/runs/10281796499

[Praveen2112]

/test-with-secrets sha=d880bd47b8a25a8bded3134a7898dfd9dcabc244

[github-actions]

The CI workflow run with tests that require additional secrets has been started: https://github.com/trinodb/trino/actions/runs/10284645638

[Praveen2112]

This run is successful - https://github.com/trinodb/trino/actions/runs/10284645638

[mosabua]

This will need to be documented.