# Getting dimensions (especially row count) of Opal tables from R/DataSHIELD session

**URL:** <https://datashield.discourse.group/t/getting-dimensions-especially-row-count-of-opal-tables-from-r-datashield-session/1210>\
**Category:** Support\
**Created:** [5 March 2025 20:25 UTC](https://datashield.discourse.group/t/getting-dimensions-especially-row-count-of-opal-tables-from-r-datashield-session/1210 "2025-03-05T20:25:47Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![BastianReiter](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@BastianReiter](https://datashield.discourse.group/u/BastianReiter)\
**Post date:** [5 March 2025 20:25 UTC](https://datashield.discourse.group/t/getting-dimensions-especially-row-count-of-opal-tables-from-r-datashield-session/1210/1 "2025-03-05T20:25:48Z")

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Hello all,

I’ve tried quite a bit with what I thought would be a fairly simple task, but now I need your help:

Is there any way to get the dimensions of Opal DB tables from a R/DataSHIELD session, but BEFORE assiging the data to symbols in the R server session? The motivation behind this is the fact that “loading” the data from Opal to R server sessions via DSI::datashield.assign takes quite a bit of time when dealing with large datasets / tables. It would be nice to know the dimensions (especially row count) before this loading, so that a user can get an estimate of how long it takes or I as a developer can inform the user about that…

Thanks for any hints!