Are you perhaps using incremental extract refresh on a data source with delete activity?
If there are any deletes on the source table (the fact that you have 293 rows now and used to have 251 seems to suggest this is the case) you can't rely on incremental refreshes.
Can you try to investigate the data?
Is there anything special about rows which are visible on Tableau side but not on PostgreSQL side?
Is this Tableau online service or your own Tableau Server?
Are you using published data sources or it's an embedded extract?
What happens if you try to create brand new extract?
1. Yes, i've deleted some rows yesterday, Tableau see correct amount of rows when I choose Live connection, i.e. the problem's not in database. It seems like tableau book contains extract, but I've tried to delete everything.
2. Yes, Tableau service is my own and there's no problem when I'm trying to refresh extract from Online tableau.
3. Actually, I don't know embedded extract or published data source. I use desktop version.
4. When I'm trying to remove extract and create new the problem remains. I really don't understand how my book keeps old data... I've already started analyzing text version of twbx book...
- Double check your source table via SQL Query (pgAdmin), may be data is actually old?
- Try to uncheck "Include external files", AFAIK it`s for file sources only.
- After that create new connection with postges tables and make full extract. If it works, replace old data connection with new one.
1.Checked database, there's no old data. (Live connection understand that and show correct amount of rows)
2.Tried uncheck "Include external files"
I think the problem is that my workbook keep some data itself. I've tried to remove extract in .twbx (opened by winrar and deleted). Further I've tried to regenerate export file,remove extract, no result.
Try to make new book, add connection and create full extract. If data will be correct, import sheets from old workbook (it will alos add old data connection) and replace source with new one.