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Release of Canton 3.6.3

Canton 3.6.3 has been released on October 20, 2026.

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Summary

This patch release fixes slow topology store lookups on Postgres that could cause high participant database load and make the ACS commitment processor fall behind on large topology states.

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What’s New

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Faster topology store lookups on Postgres

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Background

Some topology store queries filter topology transactions by a list of parties (UIDs) or namespaces. On Postgres, once that list had more than a handful of entries, the query planner switched from index lookups to a hash join over all topology transactions of the requested types. On large topology states this was orders of magnitude slower. It caused high participant database load and made the ACS commitment process fall behind.

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Specific Changes

• On Postgres, topology store queries that filter by parties or namespaces now do one index lookup per filter entry, so their cost depends on the number of filter entries rather than on the size of the topology state.
• H2 behavior is unchanged.

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Impact and Migration

Participants with large topology states see lower database load, and the ACS commitment processor no longer falls behind because of these queries. Query results are unchanged.

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Compatibility

The following Canton protocol versions are supported: Canton has been tested against the following versions of its dependencies: