[nicolasblaye]

This aims to prevent this query to append if we use the timezone specified in configuration.

[github-actions]

Benchmark                           (client)  (statement)   Mode  Cnt     Score     Error  Units
Basic.insertOneRandomNumber  clickhouse-jdbc       normal  thrpt   20   252.204 ±  33.158  ops/s
Basic.insertOneRandomNumber  clickhouse-jdbc     prepared  thrpt   20   242.658 ±  25.476  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc       normal  thrpt   20  1137.643 ± 180.147  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc     prepared  thrpt   20  1151.844 ± 115.166  ops/s

[den-crane]

But it skips to query version()

 if (serverVersion == null) {
            serverVersion = "";
        }

AFAIK it needs to implement lazy evaluation of the version?

[nicolasblaye]

Looking at the code, it does need the version for one call.
I will add the possibility to specify the version too.

if (connection.getServerVersion().compareTo("1.1.54237") > 0) { query = new StringBuilder( "SELECT database, table, name, type, default_kind as default_type, default_expression, comment "); } else { query = new StringBuilder( "SELECT database, table, name, type, default_type, default_expression, NULL AS comment "); }

[github-actions]

Benchmark                           (client)  (statement)   Mode  Cnt     Score     Error  Units
Basic.insertOneRandomNumber  clickhouse-jdbc       normal  thrpt   20   287.413 ±  29.619  ops/s
Basic.insertOneRandomNumber  clickhouse-jdbc     prepared  thrpt   20   270.213 ±  32.679  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc       normal  thrpt   20  1797.617 ± 245.494  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc     prepared  thrpt   20  2061.870 ± 224.084  ops/s

[github-actions]

Benchmark                           (client)  (statement)   Mode  Cnt     Score     Error  Units
Basic.insertOneRandomNumber  clickhouse-jdbc       normal  thrpt   20   282.646 ±  23.716  ops/s
Basic.insertOneRandomNumber  clickhouse-jdbc     prepared  thrpt   20   275.245 ±  25.968  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc       normal  thrpt   20  1785.376 ± 234.791  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc     prepared  thrpt   20  1879.875 ± 255.126  ops/s

[den-crane]

Looking at the code, it does need the version for one call.

version is used in tests. Your change skips tests / breaks CI.

[nicolasblaye]

@den-crane Sorry I don't see which test fails. mvn test returns an unrelated NPE for me. How can I run them?

[den-crane]

@nicolasblaye https://github.com/ClickHouse/clickhouse-jdbc/blob/master/clickhouse-jdbc/src/test/java/ru/yandex/clickhouse/integration/StreamSQLTest.java#L265

Some tests use getServerVersion() to make a decision does it need to run or not. Now they just skipped.

[nicolasblaye]

@den-crane As far as I know, my last two commits should make so version is still fetched by default via a select. It shouldn't change the test no?

[den-crane]

OK then. I did not check the last commit.

[zhicwu]

Thanks for the pull request @nicolasblaye. It's one-time query for connection initialization, with trivial overhead IMO. Would you mind to share the problem you're trying to resolve here? From what I saw, disabling the query may help for unit testing, plus it will slightly increase throughput.

By the way, I changed target branch to develop. Could you check the build break as well as merge conflict so that we can merge?

[nicolasblaye]

It's true that it's a small query, but we misconfigured our connection creation so we spam this query way too much (over a million time a day). Obviously, I am also fixing our connection creation issue but I figured I could also add that to the driver to avoid unnecessary (albeit very small) requests.

[github-actions]

Benchmark                           (client)  (connection)  (statement)   Mode  Cnt     Score     Error  Units
Basic.insertOneRandomNumber  clickhouse-jdbc         reuse       normal  thrpt   20   262.416 ±  30.760  ops/s
Basic.insertOneRandomNumber  clickhouse-jdbc         reuse     prepared  thrpt   20   255.047 ±  26.253  ops/s
Basic.insertOneRandomNumber  clickhouse-jdbc           new       normal  thrpt   20   250.789 ±  32.380  ops/s
Basic.insertOneRandomNumber  clickhouse-jdbc           new     prepared  thrpt   20   251.747 ±  30.619  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc         reuse       normal  thrpt   20  1218.842 ± 131.862  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc         reuse     prepared  thrpt   20  1328.295 ± 176.315  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc           new       normal  thrpt   20  1223.360 ± 167.387  ops/s
Basic.selectOneRandomNumber  clickhouse-jdbc           new     prepared  thrpt   20  1212.160 ± 163.825  ops/s

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[zhicwu]

Won't merge this pull request as this has been addressed in new JDBC driver. When serverTimeZone and serverVersion are specified, the driver will no longer issue the query on creating connection.