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Merge branch '7.2.x'
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JimGalasyn committed May 12, 2022
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16 changes: 10 additions & 6 deletions docs/developer-guide/joins/join-streams-and-tables.md
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Expand Up @@ -67,12 +67,16 @@ the order was placed, and shipped within 2 hours of the payment being received.
Joins and Windows
-----------------

ksqlDB enables grouping records that have the same key for stateful
operations, like joins, into *windows*. At the moment, ksqlDB uses a fixed grace period of 24 hours,
which means that a record can arrive out-of-order for up to 24 hours, and it's still joined correctly
based on its timestamp.
If a record arrives after the window's grace period has passed, the record is discarded and
isn't processed.
ksqlDB enables grouping records that have the same key for stateful operations,
like joins, into *windows*. A window has a _grace period_, which means that a
record can arrive out-of-order for a specified period of time, and it's still
joined correctly based on its timestamp.

If a record arrives after the window's grace period has passed, the record is
discarded and isn't processed.

For more information on grace periods, see
[Out-of-order events](../../concepts/time-and-windows-in-ksqldb-queries.md#out-of-order-events).

!!! note
Only stream-stream joins are windowed.
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