The SET command has been extended with the following syntax, to allow
setting of variables in the Impala Shell:
SET VAR:<variable_name>=<value>
The UNSET command has also been modified to allow:
UNSET VAR:<variable_name>
This patch builds on the changes in IMPALA-2179. The main change for
this patch was to ensure that all SET commands are processed by the
shell, rather than being send to the front end as a query. For this
I had to modify the command sanitization function to remove comments
that happen in front of a SET command.
Comments can be a can of worms to parse, so I tried to be as strict
as possible to avoid collateral effects. Comments are only removed
if they happen right at the beginning of the line AND before a SET
command. NO other comments are touched, including comments before,
after or within queries.
Change-Id: I87e07385122187ab8d324346499896a3dfbbafe6
Reviewed-on: http://gerrit.cloudera.org:8080/679
Reviewed-by: Casey Ching <casey@cloudera.com>
Tested-by: Internal Jenkins
This patch adds the command line option `--var` to allow the user to set
variable to be used in commands within the shell. It does *not* implement the
setting of variables through the SET command, as Hive does. This extension will
be implemented separately on IMPALA-2180.
The syntax for specifying a parameter in the command line is --var=KEY=VAL, as
for example: --var=start_date=20150101
Variables are textually replaced by their value in the Impala shell commands.
The substitution work similarly for interactive sessions as well as for command
line queries and/or scripts (-q and -f options, respectively).
Variables can be referenced as ${VAR:VAR_NAME} (case-insensitive). The form
${HIVEVAR:VAR_NAME} can also be used for compatibility with Hive scripts.
To prevent any of the reference expressions above from being replaced you can
escape them with a backslash (e.g. \${VAR:VAR_NAME} and \${HIVEVAR:VAR_NAME}).
The Impala shell's SET command now also reports the set variables and their
values.
Change-Id: Ia491fae91256334bb60c9066d119fe9a1e9779dd
Reviewed-on: http://gerrit.cloudera.org:8080/611
Reviewed-by: Casey Ching <casey@cloudera.com>
Tested-by: Internal Jenkins
