行和空间占用的空间压缩数据 [英] space taken by a row & compressed data
问题描述
使用mysql我知道一行将占用多少空间，基于数据类型
列。我也（大约）知道索引的大小。
有没有办法知道在postgresql中？
有没有办法打包（压缩）数据，与myisampack for mysql一样？
谢谢
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With mysql I know how much space a row will take, based on the datatype
of it columns. I also (approximately) know the size of indexes.
Is there a way to know that in postgresql?
Is there a way to pack (compress) data, as with myisampack for mysql?
Thank you
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推荐答案
Leonardo Francalanci写道：
Leonardo Francalanci wrote:
使用mysql我知道一行将占用多少空间，基于它的数据类型列。我也（大约）知道索引的大小。
有没有办法在postgresql中知道？
我们有一个FAQ项目。
有没有办法打包（压缩）数据，就像myisampack for mysql一样？
With mysql I know how much space a row will take, based on the datatype
of it columns. I also (approximately) know the size of indexes.
Is there a way to know that in postgresql?
We have an FAQ item about this.
Is there a way to pack (compress) data, as with myisampack for mysql?
长数据值会自动压缩。
-
Bruce Momjian | http://candle.pha.pa.us
pg *** @ candle.pha.pa.us | （610）359-1001
+如果你的生活是硬盘，|罗伯茨路13号
+基督可以成为你的备份。 |宾夕法尼亚州新城广场19073年
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Long data values are automatically compressed.
--
Bruce Momjian | http://candle.pha.pa.us
pg***@candle.pha.pa.us | (610) 359-1001
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嗨Leonardo，
Am Do，den 26.08.2004 schrieb Leonardo Francalanci 15:51：
Hi Leonardo,
Am Do, den 26.08.2004 schrieb Leonardo Francalanci um 15:51:
使用mysql我知道一行将占用多少空间，基于它的数据类型。我也（大约）知道索引的大小。
有没有办法知道在postgresql中？
有没有办法打包（压缩）数据，就像myisampack for mysql一样？
With mysql I know how much space a row will take, based on the datatype
of it columns. I also (approximately) know the size of indexes.
Is there a way to know that in postgresql?
Is there a way to pack (compress) data, as with myisampack for mysql?
在contrib目录中你会找到一些东西（dbsize左右）
来检查对象的大小（至少表格）
由于MVCC你碰巧有多个版本
同时更新了一行所以数字不是
非常精确所有的时间。
文本列等大型对象已经以压缩的
形式存储。
HTH
Tino Wildenhain
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in the contrib dir you will find something (dbsize or so)
to check for sizes of objects (at least tables)
Due to the MVCC you happen to have multiple versions
of an updated row at the same time so the numbers arent
very exact all the time.
Large objects such as text columns are stored in compressed
form already.
HTH
Tino Wildenhain
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>我们有一个关于此的常见问题项目。
该死的！我没看到那一个！对不起...
> We have an FAQ item about this.
Damn! I didn''t see that one! Sorry...
长数据值会自动压缩。
我问的原因是：
我们有一个每月存储200,000,000行的系统
（其他表每月存储10,000,000行）
每行有400列整数+ 2列（日期+整数）作为索引。
我们的系统在将行写入磁盘上的二进制文件之前压缩行。
数据通常不需要要更新/删除。
我们通常访问一行的所有列（因此每行压缩
有意义）。
有没有办法按行压缩数据？也许用
a用户自定义类型？
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The reason I''m asking is:
we have a system that stores 200,000,000 rows per month
(other tables store 10,000,000 rows per month)
Every row has 400 columns of integers + 2 columns (date+integer) as index.
Our system compresses rows before writing them to a binary file on disk.
Data don''t usually need to be updated/removed.
We usually access all columns of a row (hence compression on a per-row basis
makes sense).
Is there any way to compress data on a per-row basis? Maybe with
a User-Defined type?
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