Oracle data file type bigfile (large files) and smailfile (small files)


Bigfile (large files) : the biggest can is 4 g a database block size

Bigfile: 4 g * block_size=4 * 1024 * 1024 * 1024 * block_size


Smailfile (small files), the largest block size can be 4 m database

Smailfile: 4 m * block_size=4 * 1024 * 1024 * block_size



But every time there is always a decimal calculation, it is actually the data file is the biggest SIZE is less than the official offer several pieces, the official explanation is generally less a piece, but the actual large files less three piece of Linux environment, small file missing two pieces, I say baidu unofficial system use, but don't know whether I,



Below is the test statements:


- to create large data file test

The create bigfile in tablespace the CSB datafile 'E: \ APP \ ZHANKY \ ORADATA \ ZHANKY \ the CSB' size 1 m autoextend on next 1 m;


Query - a few pieces of

(select mount igfile,
(c. ax_data - arjun axbytes)/mount lock_size
The from dba_data_files a,
-, depending on the type of table space and database block size to calculate how much a single data file biggest G
(select tablespace_name block_size, bigfile,
Case bigfile
When 'YES' then
4 * 1024 * 1024 * 1024 * block_size
When the 'NO' then
4 * 1024 * 1024 * block_size
End max_data
The from dba_tablespaces) c
Where a.t ablespace_name=c.t ablespace_name and a.t ablespace_name in (' the CSB ', 'the SYSTEM'))


Each great god make a opinion, consult

CodePudding user response:

The building Lord your little blocks, check from?

Try

Dba_data_files
Dba_free_space

CodePudding user response:

reference 1st floor selling fruit net reply:

the original poster you less blocks, check from?

Try

Dba_data_files
Dba_free_space

I'm through the inside of the query dba_data_files maxblock to determine a total of how many pieces of a single data file,
Official document says small file is 4 m, actual it is 4 m - 1 piece, so I use to judge if it is a small file with above 4 m - 1 - maxblock but still one more

CodePudding user response:

Empty file some also have size:

Could it be that the size of the table file itself

.

CodePudding user response:

Should be

CodePudding user response:

reference 4 floor ZJHZ_ leaf response:

Should be

What you said is the operating system should be, but to create the Oracle data file after the logic structure of data file is in accordance with the table space (section, area, piece), create a file specified when the initial size, will certainly take up space, but the space should be extended space,

CodePudding user response:

Is a set of data files logic table space, should calculate the size of the entire data file

CodePudding user response:

reference ZJHZ_ leaf reply: 3/f

table space is a set of data files, logic, should calculate the total size of the data file

Yes, I said is small the size of the file table space inside a single data file, because (the official document said a single data file is 2 ^ 22 - a data Block, minus one is because as a result of the Oracle Rowid used in 22 to represent the Block number,)
So you can see 1056768-1048576=8192 just the size of a block,


: actually, I want to say is that official figures say small file data file is the most big 4 m - 1 piece, but actually we found 4 m - 1 piece of calculated is greater than the actual value of a 8192,