# Migrations of ledger data

**URL:** <https://forum.canton.network/t/migrations-of-ledger-data/3586>\
**Category:** App Development\
**Created:** [December 15, 2021, 1:56pm UTC](https://forum.canton.network/t/migrations-of-ledger-data/3586 "2021-12-15T13:56:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Ianw1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/ianw1/32/7172_2.png) [@Ianw1](https://forum.canton.network/u/Ianw1)\
**Post date:** [December 15, 2021, 1:56pm UTC](https://forum.canton.network/t/migrations-of-ledger-data/3586/1 "2021-12-15T13:56:45Z")

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Looking for a steer on the following please. How are migrations of ledger data managed :  
o In the case of incompatible, major version upgrade to underlying storage  
o In the case of cryptographic vulnerability  
o In the case of storage backend change  
Thanks

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<div class="post-metadata">

**Author:** ![bernhard](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/bernhard/32/356_2.png) [@bernhard](https://forum.canton.network/u/bernhard)\
**Post date:** [December 15, 2021, 3:32pm UTC](https://forum.canton.network/t/migrations-of-ledger-data/3586/2 "2021-12-15T15:32:15Z")

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For all ledger upgrades within a major version - eg Daml for PostgreSQL 1.17 to 1.18, the migration is fully automatic and transparent. Your driver can perform the needed migrations on startup.

In case of a major version upgrade, we aim to provide a similar experience, but won’t in all cases. A major version upgrade may require specialised migration tooling. If you are interested in a particular migration of that type, please contact Digital Asset Support.