a_horse_with_no_name

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I'm looking for job as a software developer (Java) with focus on relational database technologies (Oracle, PostgreSQL)

	8,125 reputation	bio	website		visits	member for	2 years
11027 badges		location	Munich		seen	5 hours ago

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Apr 30	comment	Oracle database created whats next? Create Schema or Create Tablespace? @DavidAldridge: interesting. I always thought that would distribute the IO load (and thus improve performance). But thinking about it, it would probably only show an improvement if the query was using parallel execution.
Apr 30	comment	Oracle database created whats next? Create Schema or Create Tablespace? @DavidAldridge: unless those tablespaces live on different (phyiscal) harddrives.
Apr 29	comment	how to check which background process are running in my oracle database? What's wrong with querying that view you already found?
Apr 29	comment	Cannot create PostgreSQL user As an alternative you can just specify `--username=postgres` as a parameter to the `createuser` command
Apr 28	comment	From SQL Server to NuoDB: Common Table Expressions, Stored Procedures and Bulk Uploads You might also want to have a look at Postgres-XC: postgres-xc.sourceforge.net
Apr 28	comment	From SQL Server to NuoDB: Common Table Expressions, Stored Procedures and Bulk Uploads Maybe if you told us why you want to switch, there might be other alternatives as well.
Apr 28	comment	From SQL Server to NuoDB: Common Table Expressions, Stored Procedures and Bulk Uploads You can download NuoDB for free and try for yourself. Or simply read the manual: nuodb.com/community/documentation.php
Apr 28	comment	Oracle 11g delete by unique key slow Is it possible, that the `insert` was trying to insert the same (unique) ID as the `delete` was trying to delete? Did you check e.g. `dba_waiters` during that time? Or `v$lock$` or `v$session_wait` or `V$SESSION_BLOCKERS`
Apr 28	comment	Getting SELECT to return a constant value even if zero rows match @NatWeiss: the implicit join in the where clause is bad coding style and should be avoided. It can lead to unwanted cartesians joins without giving you an error. And it clearly separates the two (relational) concepts of joining and filtering
Apr 28	comment	Getting SELECT to return a constant value even if zero rows match @NatWeiss: what "alternate syntax" for "other joins" are you referring to. And why do you think `left join` is not readable?
Apr 27	comment	Getting SELECT to return a constant value even if zero rows match Nice trick. The only drawback is that the values for col1 and col2 might not belong to the same row, if there is more than one matching the condition `username = 'foobar'`
Apr 27	comment	Getting SELECT to return a constant value even if zero rows match @NatWeiss: if you need a specific order, you have to supply an `order by`. The second one "creates" a virtual table with exactly one row and one column and does an outer join it (without any "real" join condition), thus you always get back at least that one row. Using `select ` in production code is bad style. Don't do it. Always list the columns you need. `select ` should only be used in ad-hoc queries.
Apr 27	comment	Creating a partial unique constraint for MySQL @RolandoMySQLDBA: a partial unique constraint does make sense. Think about a "projects" table. It contains "active" and "inactive" projects. The name of a project must be unique for all active projects. For old (inactive) projects you might allow duplicate names. There are several other scenarios where this does make sense, e.g. like this: bit.ly/fVqmEX
Apr 26	comment	Creating a partial unique constraint for MySQL I guess you'll have to live with that limitation (or go back to Postgres)
Apr 26	comment	Failover - automatic switching between servers in Postgresql 9.1 Check this out: repmgr.org
Apr 26	comment	Ideal frequency to gather table statistics in Oracle for database of 1GB in size @Sid: `estimate_percent => 100` seems way too much. Did you verify that this actually improves your execution plans? Why don't you use "ESTIMATE"? And if you don't update the table very often, there is no point in doing this every day.
Apr 26	comment	How to insert in a table with only an IDENTITY column? I prefer explicitely stating the columns: `INSERT INTO the_table (Id) VALUES (default);`
Apr 26	comment	Ideal frequency to gather table statistics in Oracle for database of 1GB in size Usually you don't need to do anything. Oracle will automatically gather table statistics for you unless you have manually turned that off. How often you do gather statistics doesn't depend on the total size of the data, but how often that data changes substantially.
Apr 26	comment	Selecting the first purchase item of each customer That's not a valid Oracle query
Apr 25	comment	Combine multiple queries into single query You might want to add a column that identifies the "source" of each row to be able to distinguish between driver, freight and locomotive.