Questions tagged [compression]
The name given to the process of encoding data such that it uses lesser number of bits as compared to the original representation.
0
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28 views
MySQL: Change compression on an existing InnoDB table
Is there any way to turn on compression for an existing table? I don't care if there's downtime for this.
The docs only mention setting compression when the table is created.
11
votes
1answer
765 views
Do SQL Server compressed indexes remain compressed on rebuild without specifying data compression?
After one rebuilds their SQL Server indexes using page compression (ALTER INDEX IX1 REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = PAGE)), do subsequent rebuilds (as done by some maintenance scripts ...
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1answer
16 views
How to analyze compression options for Azure SQL Database?
What is the most efficient way to determine whether row or page or columnstore compression (or none) would be most effective for each index in an Azure SQL Database (standard or premium tier) used for ...
2
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1answer
87 views
sparse column or DATA_COMPRESSION?
in one of my databases I have the following table:
CREATE TABLE [app].[applicantSkill](
[ApplicantSkillID] [int] IDENTITY(1,1) NOT NULL,
[applicantID] [int] NOT NULL,
[skillID] [tinyint] ...
1
vote
0answers
61 views
Testing Data Compression
We have a 1TB table that gets queried a lot. I have suggested we use Data Compression to save on space as well as help put more in memory. Because of the concern of CPU overhead, I have been tasked ...
3
votes
1answer
261 views
GZip existing varbinary(max) column in Sql Server 2008+
I have an existing legacy table that is ~180GB in size due to a client application storing PDF files as varbinary. I'd like to be able to compress that column for all rows using GZIP to help save ...
0
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1answer
24 views
After page compressing a huge table, the disk space didn't change. Do I need to shrink in any kind?
MSSQL: There is a daily partitioned table which was 2 GB and we needed to compress this table by page compression. After compression, the table size got smaller if I check from the table properties - ...
2
votes
0answers
49 views
Enable compression for SQL Server Managed Backup to Microsoft Azure
I am using SQL Server Managed Backup to Microsoft Azure for multiple databases on my SQL Server 2017. I am trying to figure out how to enable compression on some of the databases. It seems from this ...
0
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1answer
412 views
Store large compressed documents in Postgresql
Where I work we keep approximately 500,000 image files related to processing for our customer in a file system attached to our Redhat 5.11 production server. We are planning an upgrade to Redhat 7.4 ...
1
vote
1answer
90 views
Is there any string compaction option for PostgreSQL?
I have a table like this:
CREATE TABLE BLOG(
CATEGORY CHAR(32)
);
Category is a column, which stored enum values.
For example, I have 1 millions of rows and 10 unique values of Category.
Let'...
2
votes
2answers
66 views
Cancelling the rebuilding of a partition with compression
Trying to enable compression on a large table in production but we are now out of time (been running for 6.5 hours already).
What is the impact of cancelling the operation and letting it roll back?
...
2
votes
1answer
529 views
Are Postgres btree index keys compressed?
v8.4 and v9.2 (Yes, I know they're archaic and out of support, but there's nothing I can do about it.)
Some of the tables in the database which I manage (but don't design) have btree indexes on ...
1
vote
1answer
702 views
Do I gain read performance improvement by using zlib rather than snappy compression in MongoDB?
My current storage engine is WiredTiger and its compression level is as default, snappy. I've come across MongoDB documentation and it's been mentioned that using zlib compress better but needs more ...
8
votes
1answer
4k views
Compress PostgreSQL Database
I have a large PostgreSQL database over 500GB in size which is too large. Is there anyway to compress the database down to a more manageable size? I have attempted to do this with SquashFS and the ...
0
votes
1answer
209 views
Using Ola Hallengren’s Maintenance in SQL Server 2016 with TDE Enabled databases and compression
I’m using Ola Hallengren’s maintenance and backup solution and looking into leveraging TDE compression as I have all the databases in instance using TDE impression. Is there a way of getting benefit ...
1
vote
1answer
466 views
How to iterate through table and modify entrys in an “if” statement with MySQL
What I have is a table containing some temperature readings which often jump back and forth.
+------------+----------+-------------+
| timestamp | sensorID | temperature |
+------------+----------+--...
3
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0answers
152 views
When would you use InnoDB PAGE compression over InnoDB TABLE compression?
From what I understand, InnoDB table level compression is "transparent" and appears to perform well on the surface.
In what circumstances would it be beneficial to choose InnoDB page level ...
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0answers
35 views
Detect and remove entries with values jumping back and forth
I'm relatively new to databases and I'm now approaching a problem I couldn't find a solution for by myself or in forums.
I have a (InnoDB) Database which contains temperature readings which are ...
2
votes
1answer
2k views
Compression not available on SQL Server Standard? Options?
So as they say, everyday is a school day. Today I learned that my workplace, runs SQL Server Standard edition, where I would have assumed Enterprise was in place. Although in reality shouldn't be ...
12
votes
2answers
665 views
Find uncompressed size of all tables in a database
In Dynamics AX there is a caching mechanism where tables can be configured to be loaded into memory and cached. This cache is limited to a certain amount of KB to prevent memory issues. The setting I'...
5
votes
2answers
2k views
SQL Server 2012 compress column for whole table
I was wondering if SQL Server supports a kind of dictionary compression for a whole table, and not just a page.
The system I'm working on wasn't initially created for the large amounts of data it ...
2
votes
1answer
424 views
Compression setting not effective for differential backup maintenance plan?
We are taking backups (Full, Differential, and Transaction Log) of databases using the maintenance plans feature in SQL Server.
While taking the backup, I have chosen the compress option to compress ...
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vote
1answer
1k views
Compression function in Postgres
Using Java & JDBC I am storing Strings into a JSONB column in Postgres. When inserting this works great.
When retrieving values, I am running low on memory in Java because I am retrieving ...
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0answers
252 views
how do I set the compression level in tokudb
Tokudb has various algorithms, lmza, zlib, zstd etc.
These algorithms have the ability to be configured. In that, you can set the compression level to a value between 1 and 10 depending on the ...
2
votes
1answer
66 views
Spatial Index Compression
I am looking to turn page compression on on a spatial index. The instance is 2008 Enterprise. The index is pre-existing on a vendor supplied app. In searching through BOL, it states that compression ...
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vote
0answers
33 views
Wasted space for compressed SecureFile LOBs?
When using Oracle BasicFile and SecureFile one property of the implementation is that each LOB occupies multiples of the chunk size (and in case of SecureFile the smallest chunk size is the block size)...
5
votes
3answers
933 views
Enabling page compression on 1.5TB table
I need to come up with the best approach possible to enable page compression on a table 1500 GB in size, with 363,957,740 rows. The database size itself is 1.71 TB and holds archive data.
If I ...
8
votes
2answers
614 views
SQL Server 2014 compression and maximum row size
I need to create wide denormalized table with lot of decimal(26,8) columns (fewer than 1024 column limit, most of the columns would be null or zero).
I know about 8060 bytes per row limitation, so i ...
2
votes
1answer
880 views
MS SQL Server 2016 - Single Partitioned Table vs Multiply Separated Tables
We need to store a lot of logs in MS SQL Server 2016 Database for 1-1.5 year.
Income: 50 Gb of logs per month (~ 50 millions rows per month), we store all data in 6 months and shrink 50% of this data ...
6
votes
2answers
837 views
PostgreSQL network compression for result set?
I was reading about network compression with PostgreSQL to see if there was anything that offered that which would permit big result sets to transfer over the wire to remote web servers. It seems ...
10
votes
1answer
886 views
What is the row overhead when using Page Compression?
I have created a table with 650 Numeric(19,4) columns.
When I switch on Page Compression, by running
ALTER TABLE fct.MyTable REBUILD WITH (DATA_COMPRESSION = PAGE);
I get
Msg 1975, Level 16, ...
1
vote
1answer
115 views
Compress SQL Server database
Is there a way to create a SQL Server 2014 database so that all data tables will be compressed automatically?
Is there a way to compress all the existing tables of a SQL Server 2014 database?
...
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1answer
213 views
change journalCompressor to none - not default snappy
Quote from ObjectRocket Support
Hi, Fyodor! The journalCompressor setting is specifically related to
the journal files. Journals are typically not compressed because
compressing them causes ...
5
votes
1answer
5k views
Assembly is not authorized for PERMISSION_SET=UNSAFE when creating a CLR assembly
The login running all these commands is a member of sysadmin server role on a SQL 2012 Developer instance. It is the owner of the DB where this is being deployed to. EXTERNAL ACCESS ASSEMBLY ...
3
votes
1answer
1k views
Attempting to compress an existing table results in no change to the table size
There is an existing table in SQL 2012 Enterprise DB, which is ~120MB in size with ~2000 records. Its largest field is nvarchar(max) containing spongy XML (ranging from 20 to 300 kB) which on its own ...
0
votes
1answer
313 views
Does dbms_lob.getlength return the compressed or uncompressed length?
If you have tablespace compression turned on, does dbms_lob.getlength return the compressed or uncompressed length of lobs stored on that tablespace? What about LOB compression?
1
vote
1answer
87 views
Database Backup compression
I am trying to see all of my backups are compressed or not. I ran below query to check but not getting good result:
select top(10) database_name,
case when backup_size = compressed_backup_size then ...
5
votes
1answer
376 views
Backup Failure on SQL TDE Database with Maxtransfersize Specified for Compression
Recently, my company has upgraded to 2016 and enabled TDE on all of our databases. Additionally, we have the production databases replicated on high availability servers.
Our backups are taken from ...
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vote
1answer
212 views
What Backup Compression Rate Can I Expect for a Database with Mostly JPG Data?
I am considering using a database to store one or more images (.JPG) associated with a record identifier and filename.
CREATE TABLE Images (
RecordID BIGINT NOT NULL,
ImageFilename VARCHAR(50)...
0
votes
1answer
12 views
Impact of table compression on HA Synchronous-commit mode scenarios
I am working with a HA SQL 2014 instance with Synchronous-commit mode.
I did some table compression analysis with sp_estimate_data_compression_savings and I learned that table compression can be very ...
2
votes
3answers
1k views
Use of table compression in SQL Server 2014
I am going through articles about table compression in SQL Server. To me it seems quite easy to setup compressed tables and the benefits make the decision no brainer.
I wanted to consult with this ...
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vote
0answers
97 views
MariaDB replication - enabling compression
We've got a MariaDB database that's already being replicated and we wanted to turn on compression. I found the slave_compressed_protocol variable and see that it has to be turned on both on the ...
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vote
4answers
223 views
External compression tools for database backup files
Can I use external compression tools like WinZip, 7zip or winrar to compress rman backup files?
The DBMS is Oracle. A senior DBA claims that backups could be damaged by external compression tools. ...
2
votes
1answer
4k views
I wish to restore a gzipped tarball - what does mongodump --archive do? Howto do a mongorestore with --gzip?
I created a backup with
mongodump -h $RANDOM_SECONDARY_SUP -u $BACKUP_USER -p $BACKUP_PASSWD --out /data/$BACKUP_USER/sup-repl/sup_$DUMPFILE
tar cvzf /data/$BACKUP_USER/dbt/st_$DUMPFILE.tar.gz /data/...
1
vote
1answer
286 views
SQL Server Compression Estimate Is Significantly Lower When Estimating Current Compression Type
UPDATE - I originally said 'estimate significantly lower when set to 'NONE'. I'm amending that to say 'estimate significantly lower when set to [the compression in use].
When I execute the ...
12
votes
2answers
621 views
Compression on a heap
The follow is a paragraph from BOL:
New pages allocated in a heap as part of DML operations will not use PAGE compression until the heap is rebuilt. Rebuild the heap by removing and reapplying ...
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vote
1answer
115 views
How to remove Windows NTFS Compression from Oracle Database datafiles?
We know Windows NTFS compression on Oracle Database datafiles is a bad idea.
See here and here.
It prevents Asynchronous Random Disk I/O which can increase the risk of corruption and generally slow ...
0
votes
1answer
346 views
MySQL compression on Google Cloud SQL
As the Google Cloud SQL is a managed instance of MySQL under the hood, limited to an absolute max on 2nd generation machines of 100GB of RAM, should I be compressing some of my table and index data ? ...
9
votes
2answers
7k views
Please explain the difference between row and page compression
I'm trying to determine which to apply and when is the appropriate time to apply compression. I'm posting this question to get insight from this community. I have read several articles, but wanted to ...
0
votes
1answer
181 views
MySQL MyIsam Compressing tables
Im packing big MyISAM tables with myisampack and came up with the following issue. (MariaDB 10.1.14 64bit windows)
Indexes are rebuilt after packing the tablewhile running myisamchk -rq, so, it doesnt ...
