DB2數據庫中，表和表空間的大小主要受到pagesize和其對應尋址能力限制。本文將為您詳細分析DB2數據庫中表和表空間的大小的限制，供您參考，希望對您有所幫助。
在DB2 v8中，頁地址為3個字節，也就是2的24次方可用，就是16,777,216頁可以被尋址，基於這個限制得到如下表空間和表大小的限制：
# of pages Page size Limit of table / tablespace
16,777,216 4 K 64 GB
16,777,216 8 K 128 GB
16,777,216 16 K 256 GB
16,777,216 32 K 512 GB
在DB2 v9中，頁地址擴展為4個字節，也就是尋址能力提升4倍，具體的限制如下所示：
# of pages Page size Limit of table / tablespace
536,870,912 4 K 2 TB
536,870,912 8 K 4 TB
536,870,912 16 K 8 TB
536,870,912 32 K 16 TB
注意：在DB2 v8中，large類型的表空間只是為LOB和LONG數據類型所使用，而在DB2 v9中沒有類似的限制，默認的表空間類型就是large，如果從DB2 v8升級到v9就需要手動的把表空間從regular轉換為large
ALTER TABLESPACE tablespace_name CONVERT TO LARGE
DB2 v8中的典型報錯
多所有容器擴容
db2 " ALTER TABLESPACE tablespace-name EXTEND (ALL 1000000)"
DB21034E The command was processed as an SQL statement because it was not avalid Command Line Processor command. During SQL processing it returned:
SQL1139N The total size of the table space is too big. SQLSTATE=54047
對其中一個容器擴容
db2 " ALTER TABLESPACE tablespace-name EXTEND (FILE '/dir/filename' 3000000)"
DB21034E The command was processed as an SQL statement because it was not avalid Command Line Processor command. During SQL processing it returned:
SQL1139N The total size of the table space is too big. SQLSTATE=54047
加容器
db2 " ALTER TABLESPACE tablespace-name ADD (FILE '/dir/filename' 500000)"
DB21034E The command was processed as an SQL statement because it was not avalid Command Line Processor command. During SQL processing it returned:
SQL1139N The total size of the table space is too big. SQLSTATE=54047
通過檢查可以看到
LIST TABLESPACES SHOW DETAIL
...
Tablespace ID = 8
Name = tablespace-name
Type = Database managed space
Contents = Any data
State = 0x0000
Detailed explanation:
Normal
Total pages = 16388000
Useable pages = 16387840
Used pages = 16387840
Free pages = 0
High water mark (pages) = 16387840
Page size (bytes) = 4096
Extent size (pages) = 32
Prefetch size (pages) = 128
Number of containers = 4
Minimum recovery time =2009-06-26-04.47.15.000000
...
可以明顯看到頁數量已經接近了最大限制
