Is gr.getLimit() better for performance?

[Marion de Groo1]

If I set the limit on query at 1 result with gr.getLimit(1), will it be faster than without limit?

Edit: is should be setLimit(1) that was a typo

[Hitoshi Ozawa]

sys_id's are probably indexed. Indexed columns uses hash when searching instead of going through all records.

[Mark Roethof]

Hi there,

If it's an query with If and not While, then you are interested in the first record, so definitely apply setLimit, simply a best practice. 
1 remark though: this does not apply when also using getRowCount! Then don't apply setLimit.

Depending on what you are doing with the query, you might also choose hasNext instead of next.

If my answer helped you in any way, please then mark it as helpful.

Kind regards,
Mark
2020, 2021 ServiceNow Community MVP
2020, 2021 ServiceNow Developer MVP

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[Hitoshi Ozawa · Accepted solution]

As others have replied, it's setLimit().

In short, not always. Setting .setLimit() does not always imply performance improvement.

ServiceNow by default is using MySQL database. "setLimit()" probably translates to "LIMIT" in sql select statement.

In general, including LIMIT will improve performance but as can be found from reading the following threads, setting LIMIT may actually decrease performance in some circumstances. It's best practice to actually benchmark performance.

https://stackoverflow.com/questions/62814115/why-does-order-by-and-limit-1-slow-down-a-mysql-query-s...

https://stackoverflow.com/questions/4481388/why-does-mysql-higher-limit-offset-slow-the-query-down

https://stackoverflow.com/questions/34488/does-limiting-a-query-to-one-record-improve-performance

 Also, check the documentation.

For example, there is a warning on using setLimit() with deleteMultiple().

Also, do not use this method with the chooseWindow() or setLimit() methods when working with large tables.

https://developer.servicenow.com/dev.do#!/reference/api/paris/server/no-namespace/c_GlideRecordScope...

[Hitoshi Ozawa]

Also, don't use setLimit() with updateMultiple() when working with large tables.

Note: Do not use this method with the chooseWindow() or setLimit() methods when working with large tables.

https://developer.servicenow.com/dev.do#!/reference/api/paris/server/no-namespace/c_GlideRecordScope...

[Hitoshi Ozawa]

BTW, there's also chooseWindows(). According to the following statement, it seems performance consideration will be the same as with setLimit().

Note: setLimit internally calls chooseWindow.  

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0868974