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Jan
7
comment PostgreSQL 9.2 (PostGIS) performance problem
@AndyZubowsky: but still the client must read and process 150.000 rows. Check the code that is looping through those results - there you'll find your bottleneck.
Jan
4
comment how to dump MS-SQL DB using PHP with MS-SQL-SRV.?
msdn.microsoft.com/en-us/library/ms186865.aspx
Jan
3
comment What are the steps to change tables engines from MyISAM to InnoDB?
@N.B.: I didn't say you can select a row that hasn't been inserted. I said you can run insert/update/delete and select statements concurrently on the same table without the select being blocked.
Jan
3
comment What are the steps to change tables engines from MyISAM to InnoDB?
@N.B.: that is simply not true. You can very well select from a table into which a different transaction inserts rows. That is the whole point of using InnoDB (and it's MVCC implementation) over MyISAM
Jan
2
comment Automatically generate ALTER TABLE to syncronize schema on PostgreSQL
You are doing it the wrong way round. Never change the DB model "manually". Every change should be scripted in a SQL script which in turn is stored in your version control system. Then you only need to apply the necessary scripts in production (after testing them). An even better alternative is to use a tool like Liquibase or Flyway to manage all that.
Jan
1
comment Postgres - Optimizing an view dependent on an aggregate function?
You could try using distinct on or a window function to get rid of the derived table and only scan the table once then but without the execution plan and the additional information it's hard to tell.
Jan
1
comment Postgres - Optimizing an view dependent on an aggregate function?
Please read this wiki.postgresql.org/wiki/Slow_Query_Questions and add the missing information to your question (btw: the parenthesis around the actual select is totally unnecessary)
Dec
31
comment Recovery from datafiles
Doesn't support 12c though
Dec
30
comment Primary Key Question
"Repeating" the values of PK is not considered de-normalized. If the PK is really that big, that's the way it is. But (firstname, lastname, email) is not a good PK anyway (because the values of a PK should never change)
Dec
30
comment Primary Key Question
Why does a "large" primary keys (and the resulting foreign keys) make the system "heavily de-normalized"? If a PK is 5 columns, then it's 5 columns. That has nothing to do with de-normalization.
Dec
29
comment PostgreSQL Database Data File Integrity Check
Might be worth adding that since Postgres 9.3 you can optionally enable checksums
Dec
29
comment Database consistency checker in postgresql
@MartinSmith: with the new checksum in 9.3 this shouldn't be needed?
Dec
29
comment Database consistency checker in postgresql
Postgres does not need a "consistency" check. What exactly does this DBCC thing do? What exactly are you trying to achieve?
Dec
24
comment What all to start for oracle database server
@ik_zelf: not entirely true. If you want to access Oracle e.g. through JDBC you need the listener even if the JDBC app (e.g. an application server) runs on the same machine
Dec
19
comment PostgreSQL Stored Procedure Performance
It's the first time I see the claim that PL/V8 is faster than PL/pgSQL. Do you have any (published) figures to support that?
Dec
18
comment Automatically schema backup in Oracle
Do you have access to the server's filesystem? In that case you can use dbms_datapump to create a schema dump.
Dec
13
comment Does Oracle 10g Express Edition have enough storage?
I would assume that 5G should be enough for what you describe. But 10g is already outdated. For any new project you should use the current version which is 11g (which also has a max. size of 11GB instead of "just" 5)
Dec
11
comment Save and restore specific tables
Using DataPump is a good way to do that.
Dec
11
comment Why NOSql should be more performant than RDBMS under structured data loads?
Any modern RDBMS can handle "millions of rows". Many of the NoSQL DBMS are faster because they sacrifice some of the ACID principles that the relationals ones implement or other features that are common in the "relational world. e.g. they are "eventually consistent" or they don't support transactions, or they don't support fine grained locking, ...
Dec
10
comment Partitioning MySQL vs PostgreSQL
"does not directly support foreign keys and partitions" - if you define the FK constraint for each child table this seems to be working pretty well. Did you mean that with "not directly"? - that you need to create the FK for each partition?