[ParsedQuery] Check is_read_only_query too slow

[vuongtlt13]

Bug description

Problem

First, I have a sql statement with length is 17121. I need check **is_read_only_query**

Logic for checking is_read_only_query is at superset/db_engine_specs/base.py#L2027

Test result

As you can see:

• For current ParsedQuery class:
  Each function in is_select, is_explain, is_show will format sql statement by calling sqlparse.format function. But it takes quite long (~0.332s for one call). So you need to call 3 times for checking is_read_only_query --> Total time: 0.9818s

Solution

I wrote an PR to reduce time for checking is_read_only_query at #29557

Please help me to review it

How to reproduce the bug

Go to a dashboard and check time for loading result

Screenshots/recordings

No response

Superset version

master / latest-dev

Python version

3.9

Node version

16

Browser

Chrome

Additional context

No response

Checklist

• I have searched Superset docs and Slack and didn't find a solution to my problem.
• I have searched the GitHub issue tracker and didn't find a similar bug report.
• I have checked Superset's logs for errors and if I found a relevant Python stacktrace, I included it here as text in the "additional context" section.

[dosubot]

Hey there, @vuongtlt13! 👋 I'm here to assist you with any bugs, questions, or contributions. Let's squash those bugs together!

The pull request you mentioned introduces the is_select_query method and uses it within the is_readonly_query method to improve performance. This change reduces the number of times the sqlparse.format function is called, which significantly decreases the time required to check if a query is read-only.

Here is the relevant code from the pull request:

@classmethod
def is_readonly_query(cls, parsed_query: ParsedQuery) -> bool:
    """
    Pessimistic readonly, 100% sure statement won't mutate anything.
    """
    return KustoKqlEngineSpec.is_select_query(
        parsed_query
    ) or parsed_query.sql.startswith(".show")

@classmethod
def is_select_query(cls, parsed_query: ParsedQuery) -> bool:
    return not parsed_query.sql.startswith(".")

This change ensures that the is_readonly_query method only calls sqlparse.format once, reducing the total time from approximately 0.9818s to 0.3278s ^[1].

Additionally, there are existing unit tests for the is_readonly_query method that cover various scenarios for both SQL and KQL queries. These tests ensure that the method correctly identifies read-only queries ^[2][3][4].

You can review the pull request and run the tests to verify the improvements.

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