# Internal Tag Historian External Access

**URL:** <https://forum.inductiveautomation.com/t/internal-tag-historian-external-access/59748>\
**Category:** Ignition\
**Tags:** database, ignition81\
**Created:** [May 18, 2022, 8:08pm UTC](https://forum.inductiveautomation.com/t/internal-tag-historian-external-access/59748 "2022-05-18T20:08:27Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [May 18, 2022, 8:08pm UTC](https://forum.inductiveautomation.com/t/internal-tag-historian-external-access/59748/1 "2022-05-18T20:08:27Z")

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Is the internal tag historian an SQL database? Which one?  
Is there any way to access the internal tag historian database from an external application?

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [May 18, 2022, 8:10pm UTC](https://forum.inductiveautomation.com/t/internal-tag-historian-external-access/59748/2 "2022-05-18T20:10:56Z")

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IIRC, it is SQLite. Ignition holds the file open, so it is not accessible externally while Ignition is running. (SQLite is single-threaded, single-user technology.)

If you need simultaneous access, use a “real” database.

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<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [May 18, 2022, 8:13pm UTC](https://forum.inductiveautomation.com/t/internal-tag-historian-external-access/59748/3 "2022-05-18T20:13:31Z")

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That’s what I suspected, otherwise people would work around the Tag Historian module to avoid the cost.

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [May 18, 2022, 8:15pm UTC](https://forum.inductiveautomation.com/t/internal-tag-historian-external-access/59748/4 "2022-05-18T20:15:24Z")

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You can implement an API via WebDev if you must. Internal queries will be done one at a time correctly.