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1500 questions
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6 answers

Is there any limit to the number of databases you can put on one SQL server?

I'm setting up a SaaS system, where we're planning to give each customer their own database. The system is already set up so that we can easily scale out to additional servers if the load becomes too great; we're hoping to have thousands, or even…
Shaul Behr
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I need to run VACUUM FULL with no available disk space

I have one table that is taking up close to 90% of hd space on our server. I have decided to drop a few columns to free up space. But I need to return the space to the OS. The problem, though, is that I'm not sure what will happen if I run VACUUM…
Justin Rhyne
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Order by column should have index or not?

I have added indexes to table which are used for searching result. I am showing results by ASC or DESC order. So that column should have index or not? I have 2 more indexes on that table. How performance will affect by making or not making index to…
Somnath Muluk
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select rows where column contains same data in more than one record

I have a table that has a column called article_title. Let's say the table name is articles. I need to find out the records where the article_title data is the same on more than one record. Here's what I've got: select a.* from articles a where…
somejkuser
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5 answers

How to estimate/predict data size and index size of a table in MySQL

I am finding what is the best way to estimate size of a table for that I have studied lot of blogs and forums but unable to find any accurate answer For example, we have a table City with InnoDB engine,lets say in future (in next 1 year) it will…
Abdul Manaf
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46
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5 answers

How to SELECT from SHOW TABLE STATUS results

I'd like to limit the rows and columns that come back from the SHOW TABLE STATUS command in MySQL 5.1. Is there a way to get this same information through a SELECT statement so I can manipulate the results in a normal way?
Leopd
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9 answers

Asked to Not Use Transactions and to Use A Workaround to Simulate One

I've been developing T-SQL for several years and am always digging in further, continuing to learn all I can about all aspects of the language. I recently started working at a new company and have received what I think is an odd suggestion regarding…
Forrest
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12 answers

How could DBAs be more 'programmer friendly'?

The answers and comments on the dba.se version and programmers.se version of the question "What are the arguments against or for putting application logic in the database layer?" are very revealing about the divide between DBAs and programmers in…
Jack Douglas
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Scalability limitations of PostgreSQL and MySQL

I've heard that performance of non-sharded relational database such as MySQL or PostgreSQL "breaks" beyond 10 TB. I suspect that limits as such do exist as one would not come up with Netezza, Greenplum, or Vertica, etc, however I would like to ask…
Edmon
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What does IDLE state denotes in a row of pg_stat_activity?

Can someone resolve my below doubts about pg_stat_activity in terms of postgres 9.5? Can some let me know what does the state IDLE denotes in the row of pg_stat_activity? Is it like it checks all the open connections to postgres and if the…
tuk
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9 answers

How should deletions be handled in the database?

I'd like to implement an "undelete" feature in a web application such that a user can change her mind and recover a deleted record. Thoughts on how to implement this? Some options I've considered are actually deleting the record in question and…
Abie
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Would index lookup be noticeably faster with char vs varchar when all values are 36 chars

I have a legacy schema (disclaimer!) that uses a hash-based generated id for the primary key for all tables (there are many). An example of such an id is: 922475bb-ad93-43ee-9487-d2671b886479 There is no possible hope of changing this approach,…
Bohemian
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4 answers

Force PostgreSQL clients to use SSL?

I have configured ssl = on in postgresql.conf (and installed a certificate etcetera). Does this ensure that all clients will always connect over SSL? (I.e. does ssl = on it make it impossible to connect without SSL encryption?) Are there other ways…
KajMagnus
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4 answers

Can I install SQL Server Management Studio locally?

Can I install SQL Server Management Studio on my desktop to access a database on a SQL Server 2012 instance? If so, where can I find the installer? Google searches only return 'express' versions whereas, I am looking for the full SQL Server…
pgunston
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3 answers

Replace a materialized view in Postgres

I have a materialized view in Postgres 9.3 that I'd like to update with new columns. However, other materialized views also depend upon this view, and the error message indicates that dropping a view isn't possible when other objects depend on it. …
John
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