phoenix-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "James Taylor (JIRA)" <>
Subject [jira] [Commented] (PHOENIX-14) UPSERT hint to avoid WAL writes
Date Fri, 31 Jan 2014 01:50:10 GMT


James Taylor commented on PHOENIX-14:

There's an existing boolean property, disableWAL, that can be set with the CREATE TABLE statement
and modified with an ALTER TABLE statement. Doing it per upsert is a bit painful, as sometimes
the upsert is processed on the client and sometimes on the server. We'd need to pass around
the disableWAL attribute through all these and worry about resolving multiple upserts to the
same row, some with disableWAL, some not, and the intersection between them.

The use cases I've seen for disabling the WAL are all supported by specifying it on a per
table basis. For example, in the case of an initial seed of a table, followed by "normal"
operation, you could do the following:

ALTER TABLE t SET disableWAL=true; initial seed...
ALTER TABLE t SET disableWAL=false;
...continue with normal operation...

> UPSERT hint to avoid WAL writes
> -------------------------------
>                 Key: PHOENIX-14
>                 URL:
>             Project: Phoenix
>          Issue Type: Improvement
>            Reporter: Lars Hofhansl
> Since HBASE-7801 (0.94.7) HBase supports durability hints for Put and Delete operations.

> We should support these via an UPSERT hint.
> At least /*+ SKIP_WAL */ to skip all WAL writes.
> Later we can add
> /*+ ASYNC_WAL */
> /*+ SYNC_WAL */
> /*+ FSYNC_WAL */

This message was sent by Atlassian JIRA

View raw message