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comment Build PL/pgSQL function to request the depth of relations
You are mixing explicit joins and implicit joins in the recursive part of your CTE: FROM ebenen, buchstelle bst JOIN ... Don't do that. That creates a cartesian product between ebenen and buchstelle. I'm pretty sure that's not what you intended
1h
comment Build PL/pgSQL function to request the depth of relations
Did you try a recursive CTE?
1d
revised 1 TB Database import, best options?
edited tags
1d
comment MySQL CHAR(500)?
Again: did you do any testing that confirms your assumption? I would very much doubt that you'd be able to measure a difference.
1d
comment MySQL CHAR(500)?
"and VARCHAR is a less efficient storage mechanism" - how do you know that? Did you do any performance testing?
2d
comment DBMS database management system
This question appears to be off-topic because it does not show any research effort
2d
comment Why would SELECT * be magnitudes faster than SELECT foo?
The first statements most probably uses the primary key index on id to find the first row. The second one needs to sort the complete result on the (un indexed) val column.
2d
comment get average of rating using group by and then finally overall rating . Example below
Which DBMS are you using? Postgres? Oracle? DB2?
2d
revised get average of rating using group by and then finally overall rating . Example below
fixed code formatting
Jul
26
comment Search a alphanumeric value from varchar column in DB2
Cross post: stackoverflow.com/q/24969813/330315
Jul
26
comment Auto increment char varying column prefixed with some characters
"can't we just make any varchar as auto-increament" - that is not the correct question. What you are trying to achieve simply doesn't make sense.
Jul
26
comment How to generate the E-R Diagram of Wordpress using mySQL Workbench
Most probably Wordpress isn't using any foreign keys (as so many off-the-shelf products...)
Jul
26
comment Auto increment char varying column prefixed with some characters
Why would you want to do that? If every key value has the prefix PAT there is no sense in storing it. Create a serial column and a view that formats the number as desired. Additionally: the value of a primary key has no meaning whatsoever. You should not care about the values in that column, the only thing you need to care about is that they are unique.
Jul
26
revised Auto increment char varying column prefixed with some characters
deleted 54 characters in body; edited title
Jul
25
revised Inner Join or what else?
edited tags
Jul
25
revised Risk of disabling page locking
edited tags
Jul
25
comment Postgres vs Mongodb, Suggestions to improve mongodb performance
Relational databases have been designed for ages to do efficient aggregation. My understanding is that aggregation (of mass data) is not the sweet spot of NoSQL databases - they are intended and designed for other areas. See for example this blog posting: tapoueh.org/blog/2014/02/…
Jul
25
revised Postgres vs Mongodb, Suggestions to improve mongodb performance
added 75 characters in body
Jul
25
comment Index on 'GROUP BY' with functions
MySQL doesn't support indexes on expressions or functions
Jul
25
revised Index on 'GROUP BY' with functions
edited tags