Tableau does not grant write access to our internal database for pretty obvious reasons - a user could inadvertently make a mistake and destroy / alter information in the database and bring down the server entirely.
If you use Google, you can find people who have documented how to get full access to our database - but if you make any changes to it, you are no longer in a supported configuration - If you have any problems, Tableau support will need you to "revert" to an unmodified version of the database. Changes you make could also break upgrades / migration later on. I would not consider doing this in production unless YOU have significant resources to put towards testing the unsupported changes you make.
Hope this helps a little.
My aim was to change time zone, and was able to do it without gaining write access. I was able to do it via the properties by changing the variable.
Thank you for your help.
Can you explain what you did to accomplish this? I can easily do that if I'm writing SQL, but is there something native in Tableau to accomplish this?
I'm certain you can change the timezone information in any Postgres database using pgadmin3 or SQL statements.
That being said, this is the kind of change that I'd strongly recommend against making. A lot of database scripts for migration are run during upgrades, and I've seen seemingly harmless customer mods to our postgres database ("seemingly harmless" because the running server appeared unaffected by the mods) throw the scripts off in bad ways.
Instead, what I've generally done is used a calculated field and DATEADD to have a local time column. Furthermore, you can use a parameter so that the plus or minus to UTC is something controllable.
Thanks to all who have responded to this discussion. I have finally resolved this issue and have set WRITE access to server and also changed Timezone in simple steps. Please email me in person (firstname.lastname@example.org) if you need to know the steps for this implementation.