1、SGA、PGA应用状况查问；select name,total,round(total-free,2) used, round(free,2) free,round((total-free)/total*100,2) pctused from

(select 'SGA' name,(select sum(value/1024/1024) from v$sga) total,

(select sum(bytes/1024/1024) from v$sgastat where name='free memory')free from dual)

union

select name,total,round(used,2)used,round(total-used,2)free,round(used/total*100,2)pctused from (

select 'PGA' name,(select value/1024/1024 total from v$pgastat where name='aggregate PGA target parameter')total,

(select value/1024/1024 used from v$pgastat where name='total PGA allocated')used from dual);

2、内存使用率；-- pctused: 使用率

select * from (

select name,total,round(total-free,2) used, round(free,2) free,round((total-free)/total*100,2) pctused from

(select 'SGA' name,(select sum(value/1024/1024) from v$sga) total,

(select sum(bytes/1024/1024) from v$sgastat where name='free memory')free from dual)

union

select name,total,round(used,2)used,round(total-used,2)free,round(used/total*100,2)pctused from (

select 'PGA' name,(select value/1024/1024 total from v$pgastat where name='aggregate PGA target parameter')total,

(select value/1024/1024 used from v$pgastat where name='total PGA allocated')used from dual)

union

select name,round(total,2) total,round((total-free),2) used,round(free,2) free,round((total-free)/total*100,2) pctused from (

select 'Shared pool' name,(select sum(bytes/1024/1024) from v$sgastat where pool='shared pool')total,

(select bytes/1024/1024 from v$sgastat where name='free memory' and pool='shared pool') free from dual)

union

select name,round(total,2)total,round(total-free,2) used,round(free,2) free,round((total-free)/total,2) pctused from (

select 'Default pool' name,( select a.cnum_repl*(select value from v$parameter where name='db_block_size')/1024/1024 total from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='DEFAULT' and p.block_size=(select value from v$parameter where name='db_block_size')) total,

(select a.anum_repl*(select value from v$parameter where name='db_block_size')/1024/1024 free from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='DEFAULT' and p.block_size=(select value from v$parameter where name='db_block_size')) free from dual)

union

select name,nvl(round(total,2),0)total,nvl(round(total-free,2),0) used,nvl(round(free,2),0) free,nvl(round((total-free)/total,2),0) pctused from (

select 'KEEP pool' name,(select a.cnum_repl*(select value from v$parameter where name='db_block_size')/1024/1024 total from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='KEEP' and p.block_size=(select value from v$parameter where name='db_block_size')) total,

(select a.anum_repl*(select value from v$parameter where name='db_block_size')/1024/1024 free from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='KEEP' and p.block_size=(select value from v$parameter where name='db_block_size')) free from dual)

union

select name,nvl(round(total,2),0)total,nvl(round(total-free,2),0) used,nvl(round(free,2),0) free,nvl(round((total-free)/total,2),0) pctused from (

select 'RECYCLE pool' name,( select a.cnum_repl*(select value from v$parameter where name='db_block_size')/1024/1024 total from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='RECYCLE' and p.block_size=(select value from v$parameter where name='db_block_size')) total,

(select a.anum_repl*(select value from v$parameter where name='db_block_size')/1024/1024 free from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='RECYCLE' and p.block_size=(select value from v$parameter where name='db_block_size')) free from dual)

union

select name,nvl(round(total,2),0)total,nvl(round(total-free,2),0) used,nvl(round(free,2),0) free,nvl(round((total-free)/total,2),0) pctused from(

select 'DEFAULT 16K buffer cache' name,(select a.cnum_repl*16/1024 total from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='DEFAULT' and p.block_size=16384) total,

(select a.anum_repl*16/1024 free from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='DEFAULT' and p.block_size=16384) free from dual)

union

select name,nvl(round(total,2),0)total,nvl(round(total-free,2),0) used,nvl(round(free,2),0) free,nvl(round((total-free)/total,2),0) pctused from(

select 'DEFAULT 32K buffer cache' name,(select a.cnum_repl*32/1024 total from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='DEFAULT' and p.block_size=32768) total,

(select a.anum_repl*32/1024 free from x$kcbwds a, v$buffer_pool p

where a.set_id=p.LO_SETID and p.name='DEFAULT' and p.block_size=32768) free from dual)

union

select name,total,total-free used,free, (total-free)/total*100 pctused from (

select 'Java Pool' name,(select sum(bytes/1024/1024) total from v$sgastat where pool='java pool' group by pool)total,

( select bytes/1024/1024 free from v$sgastat where pool='java pool' and name='free memory')free from dual)

union

select name,Round(total,2),round(total-free,2) used,round(free,2) free, round((total-free)/total*100,2) pctused from (

select 'Large Pool' name,(select sum(bytes/1024/1024) total from v$sgastat where pool='large pool' group by pool)total,

( select bytes/1024/1024 free from v$sgastat where pool='large pool' and name='free memory')free from dual)

order by pctused desc);

3、查看内存应用的其它指标select * from v$sga_dynamic_components;

select * from v$pgastat;

-- 查问share pool的闲暇内存

select a.*,round(a.bytes/1024/1024,2) M from v$sgastat a where a.NAME = 'free memory';

-- 通过上面的sql查问占用share pool内存大于10M的sql

SELECT substr(sql_text,1,100) "Stmt", count(*),

sum(sharable_mem) "Mem",

sum(users_opening) "Open",

sum(executions) "Exec"

FROM v$sql

GROUP BY substr(sql_text,1,100)

HAVING sum(sharable_mem) > 10000000;

-- 查问一下version count过高的语句

SELECT address,

sql_id,

hash_value,

version_count,

users_opening,

users_executing,

sql_text

FROM v$sqlarea WHERE version_count > 10;