[
https://issues.apache.org/jira/browse/TRAFODION-2521?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15937634#comment-15937634
]
ASF GitHub Bot commented on TRAFODION-2521:
-------------------------------------------
Github user liuyu000 commented on a diff in the pull request:
https://github.com/apache/incubator-trafodion/pull/995#discussion_r107580922
--- Diff: docs/cqd_reference/src/asciidoc/_chapters/query_execution.adoc ---
@@ -237,3 +237,54 @@ If you enable small scanner on large size scan
incorrectly, then you are likely
| *Deprecated In Release* | Not applicable.
|===
+<<<
+[[scratch-dirs]]
+== SCRATCH_DIRS
+
+[cols="25%h,75%"]
+|===
+| *Description* | Allows a CQD specification to override
the envvar settings for scatch and temporary file locations, which gives user
more flexibility to change scratch directory locations.
+| *Values* |
+Scratch disk locations for overflow (linux path names).
+
+Multiple locations can be specified, separated by a colon. For example,
/tmp/scratch1:/tmp/scratch2.
+
+| *Usage* a|
+
+*Two ways to change scratch directory location permanently*:
+
+* Specify this location at installation time.
+
++
+Currently the scratch directory locations are set at installation time.
The layer of scratch and temporary file system that manages the scratch file
creation and reads the envvar in $TRAF_HOME/etc/ms.env to determine where to
create the scratch files.
+
++
+The CQD will override envvar settings, there are two envvar settings: one
is STFS_HDD_LOACTION (default), the other is STFS_SSD_LOCATION (SSD disk).
+
++
+If the CQD is not set (empty), the envvar setting will work.
+
++
+The requirement is that the directories MUST exist on every node and
Trafodion user will need permission to write to those directories. If not, an
error will be returned when a query involving sort/hash overflow is executed.
+
+* Set it in sqconfig.
+
+*One way to change scratch directory location temporarily*:
+
+* If the scratch directory location is not set at installation time, this
CQD is valid only for the duration of the session.
+
++
+These settings will not be stored in $TRAF_HOME/etc/ms.env and will
override the envvar settings as long as the CQD is in effect.
+
+| *Production Usage* | Please contact {project-support}.
+| *Impact* |
+More volume of data can be processed. For example, large data set.
+
+Larger disk space can process larger data set.
--- End diff --
Got, thanks Dave. :)
> Add SCRATCH_DISKS CQD
> ---------------------
>
> Key: TRAFODION-2521
> URL: https://issues.apache.org/jira/browse/TRAFODION-2521
> Project: Apache Trafodion
> Issue Type: Documentation
> Reporter: Liu Yu
> Assignee: Liu Yu
>
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
