The name given to the process of encoding data such that it uses lesser number of bits as compared to the original representation.

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1k views

TokuDB optimize table does not reclaim disk space

Was running an optimize table command against one of my tables about 11Gig in size, surprisingly used disk space grew by 2Gig immediately after optimization process finished. I would expect the ...
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2answers
14k views

What is the most effective way to compress and store a SQL Server backup? [closed]

I've been doing some testing of different methods for compressing and storing SQL Server backups (using SQL Server 2008 R2 Enterprise edition), and I'm wondering what the most effective compression ...
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1answer
944 views

Alter table move taking long time

I'm currently trying to compress a table in Oracle with the following statements: ALTER TABLE MYTABLE COMPRESS FOR OLTP; ALTER TABLE MOVE; My question is: the MOVE operation is taking forever and ...
2
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2answers
252 views

Can I restore an uncompressed differential backup after a compressed full backup?

If we enable compression on database backups (because the database backup size is huge) but don't enable it on differential which are relatively small in size, will a restore work? Because the full ...
5
votes
2answers
543 views

When should tables NOT be compressed

We have two servers. One we just compressed, but I took over this little project and this guy says some tables are not good candidates. As with many others, performance is -critical-. Is it accurate ...
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1answer
338 views

Database size not reduced after compressing tables

Using Data Compression, my table size was reduced from 1770 MB to 250 MB, but the database size was not reduced. Why?
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1answer
2k views

Compress backup file using T-SQL

Is it possible to compress a backup file to .zip (or another) in a stored procedure invoked from a maintenance plan? My maintenance plan contains these steps: check DB (consistency, re_index, maybe ...
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1answer
3k views

Is SQL Server data compression categorically good for read-only databases?

Some literature on SQL Server data compression I read state that the write cost increases to about four times what would normally be required. It also seems to imply that this is the primary downside ...
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1answer
963 views

Compressions vs shrinking a database

Is compression and shrinking a database in SQL Server same? If I compress a table, will it decrease query performance and DML?
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2answers
4k views

Is data retrieved from SQL Server compressed for transmission?

Is data retrieved from Microsoft SQL Server compressed? If this is controlled by the connection string, is there any simple way to tell if any particular app is using it? I'm examining analysis tools,...
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1answer
549 views

Which Database to choose: MySQL or Oracle

I have an application generating time series data (32 channels, 22KHz, 6 secs) once a minute. These have to be stored in a database. At the moment I'm using MySQL with InnoDB tables (file_per_table,...
2
votes
1answer
301 views

Why 2 allocation units during online index rebuild to different file group?

I'm in the process of rebuilding the clustered index of a big table to a different file group. I'm monitoring the rebuild process using sys.system_internals_allocation_units. I'm 3h in but not done ...
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2answers
2k views

Does adding page compression to a table also compress existing indexes?

I am creating a series of new tables that will have page level compression enabled. Will this affect the indexes as well, or will I have to also specify compression when creating the indexes? create ...
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2answers
2k views

PAGE compression in SQL Server effect on running queries

I am planning to apply PAGE compression to some of the big tables in my database (DW to be precise). These tables are fairly big with over 15 Billion rows. When I applied the compression in test ...
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1answer
387 views

What program to use for the best compression ratio for DB2 log files?

What linux program to use to compress DB2 log files with the best compression ratio? UPDATE I thought that these log files would be text type files. But viewing them didn't prove this. I tried to ...
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votes
3answers
3k views

Set Backup Compression on SQL Server 2008R2 on by default

I can't seem to find the option to set the server property that will enable compression on SQL database backup to be ON by default, so I don't have to manually set it every time. Can anyone point me ...
3
votes
2answers
305 views

SQL database backups methods-tools-procedures

Currently, I am investigating some way to more efficiently backup 4 Production SQL Databases (3 different servers/instances) and would like to know if anyone else has had the problems we are having ...
2
votes
1answer
427 views

myisampack running really slow for large DBs

I was going through compressing a bunch of archival myisam tables using myisampack It was making decent progress until it got to the most recent tables. The overall database is a set of archives for ...
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1answer
127 views

Oracle SecureFile Compression

Where can I read database compression properties after the creation of an oracle database / tables? Is there a special view where the info is stored and can be retieved?
5
votes
1answer
566 views

SQL 2008 Merge Replication and table-level data compression

What would happen if you enable data compression (either row or page-level) on a replicated table (merge replication) where the publisher is SQL 2008 Enterprise (Supports data compression) and the ...
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3answers
4k views

Backup Compression in SQL Server 2005

I noticed that simply zipping my backup files reduces the space used by 70% My idea was to, initially, backup the databases to a local server; then, using Bacula or Cobian (I don't have a budget), ...
5
votes
1answer
890 views

How does table compression affect SQL Server's buffer pool?

I'm curious as to how SQL Server's buffer pool is affected by compressed data tables. Is the data in memory compressed, just as it is on disk, or is it fully decompressed? If the data is stored ...