Discussion :

[Cathy]

Bonjour,

Savez-vous comment je peux connaitre la valeur de ce paramètre "file system buffer size". Existe t-il une commande ? Je suis sur un AIX 5.3 (64bits)


Merci de votre aide,

Cat

[Mr6]

Salut !

Je me demande si ce n'est pas la valeur LGT dans la description d'un VG.

@+
Mr6

[Cathy]

Voilà ce que j'ai trouvé :

A UNIX system reads entire operating system blocks from the disk. If the database block size is smaller than the UNIX file system buffer size, I/O bandwidth is inefficient. If you adjust the Oracle database block size to be a multiple of the operating system block size, you can increase performance by up to five percent.

You can configure the Oracle database block size for better I/O throughput. On AIX, you can set the value of the DB_BLOCK_SIZE initialization parameter to between 2 KB to 32 KB, with a default of 4 KB. If the Oracle database is installed on a journaled file system, then the block size should be a multiple of the file system blocksize (4 KB on AIX). For databases on raw partitions, the Oracle database block size is a multiple of the operating system physical block size (512 bytes on AIX).Oracle Corporation recommends smaller Oracle database block sizes (2 KB or 4 KB) for online transaction processing (OLTP) or mixed workload environments and larger block sizes (8 KB, 16 KB, or 32 KB) for decision support system (DSS) workload environments.