hive3和2的区别 hive3跟hive2对比

Hibernate3 的一些问题 
 
做Hibernate第一个小例子就失败，原来是Hibernate2和Hibernate3的区别造成的 
 
我用的是Hibernate3，而书上的例子、网上的例子全都是Hibernate2的，在网上的例子中｛Eclipse快速上手Hibernate（）｝提供的源代码，有如下两行：
import net.sf.hibernate.*;
import net.sf.hibernate.cfg.*;
搞了好几天，就是找不到 net.sf.hibernate.cfg 包，后来终于在找到一篇文章，说明了Hibernate2升级为Hibernate3的注意事项，下面是原文：
================================
选择自 chinaewolf 的 Blog 
hibernate2 升级为hibernate3的需要注意的事项
(chinaewolf的工作日记)
目的,主要是那当前的项目练手,熟悉一下hibernate2和hibernate3的差别,给当前项目一点扩展的空间. 
1.首先将hibernate2.jar替换为hibernate3.jar(hibernate-3.0.5)
hibernate-tools.jar也替换成新的(从hibernate-tools-3.0.0.alpha4a找出来的)
2.将所有程序中的net.sf.hibernate替换为org.hibernate.
3.但是有例外
net.sf.hibernate.expression.Expression换为org.hibernate.criterion.Expression
如果用eclipse,用ctrl+shift+o快捷键可以加快速度:)
4.在使用hql查询时将
createSQLQuery(hql,"c",EZCampaignDTO.class);改为createSQLQuery(hql).addEntity("c",EZCampaignDTO.class);
5.在批量插入时
将原来的int size = ((SessionFactoryImpl)(session.getSessionFactory())).getJdbcBatchSize()
改为int size = ((SessionFactoryImpl)(session.getSessionFactory())).getSettings().getJdbcBatchSize();
6.在计算count时
将原来的int size = ((Integer) session.iterate(hql).next()).intValue();
改为int size = ((Integer) session.createQuery(hql).iterate().next()).intValue();
其中hql="select count(*) from " + DAOVar.contactClass;
7.还有就是把.hbm中的hibernate-mapping-2.0.dtd替换为hibernate-mapping-3.0.dtd
Hibernate Mapping DTD 2.0替换为Hibernate Mapping DTD 3.0
8.hibernate.cfg.xml中
Hibernate Mapping DTD 2.0替换为Hibernate Mapping DTD 3.0
org.hibernate.dialect.SQLServerDialect
9.hibernate.properties中类似
10.cache-config.xml中
替换为11.classeshibernate.properties中
hibernate.cache.provider_class=org.hibernate.cache.EhCacheProvider
hibernate.dialect=org.hibernate.dialect.SQLServerDialect
晕s了,怎么这里还有
还是用编辑器暴力替换一下吧干脆
然后部署,集成测试,希望一切ok
结果咣铛,还是报错
12.在自动外部模块部分有一个功能是根据模版自动生成.hbm文件在load,结果出来的.hbm中有问题:
生成的 其中mapped="false" 出错.
找了半天才发现在网上的hibernate-mapping-3.0.dtd文件有支持mapped="false"这个属性.而本地的hebernate3.0.5中的
hibernate-mapping-3.0.dtd文件没有这个属性.晕,hibernate也太不负责了吧. 解决办法把hibernate-mapping-3.0.dtd
copy到jboss/bin目录下然后,在template文件中
然后他会在jboss/bin目录下读取该文件
13.重新测试,还是咣铛
发现子类读父类数据时抛出异常
"org.hibernate.LazyInitializationException: could not initialize proxy"
延迟抓取出的错,hb3对many-to-one的默认处理是lazy = "proxy"
没有搞懂到底怎么回事,把所有many-to-one,one-to-one都加上lazy="false"
再测试终于大功告成  
Oracle维护常用SQL语句 
 
Oracle维护常用SQL语句        用户评分:/5 
差好
作者： Administrator  
2004-09-16  
1、查看表空间的名称及大小 
select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size 
from dba_tablespaces t, dba_data_files d 
where t.tablespace_name = d.tablespace_name 
group by t.tablespace_name; 2、查看表空间物理文件的名称及大小 
select tablespace_name, file_id, file_name, 
round(bytes/(1024*1024),0) total_space 
from dba_data_files 
order by tablespace_name; 3、查看回滚段名称及大小 
select segment_name, tablespace_name, r.status, 
(initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent, 
max_extents, v.curext CurExtent 
From dba_rollback_segs r, v$rollstat v 
Where r.segment_id = v.usn(+) 
order by segment_name ; 4、查看控制文件 
select name from v$controlfile; 5、查看日志文件 
select member from v$logfile; 6、查看表空间的使用情况 
select sum(bytes)/(1024*1024) as free_space,tablespace_name 
from dba_free_space 
group by tablespace_name; SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE, 
(B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE" 
FROM SYS.SM$TS_AVAIL A,SYS.SM$TS_USED B,SYS.SM$TS_FREE C 
WHERE A.TABLESPACE_NAME=B.TABLESPACE_NAME AND A.TABLESPACE_NAME=C.TABLESPACE_NAME; 7、查看数据库库对象 
select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status; 8、查看数据库的版本　 
Select version FROM Product_component_version 
Where SUBSTR(PRODUCT,1,6)='Oracle'; 9、查看数据库的创建日期和归档方式 
Select Created, Log_Mode, Log_Mode From V$Database; 10、捕捉运行很久的SQL 
column username format a12 
column opname format a16 
column progress format a8 select username,sid,opname, 
round(sofar*100 / totalwork,0) || '%' as progress, 
time_remaining,sql_text 
from v$session_longops , v$sql 
where time_remaining <> 0 
and sql_address = address 
and sql_hash_value = hash_value 
/ 11、查看数据表的参数信息 
SELECT partition_name, high_value, high_value_length, tablespace_name, 
pct_free, pct_used, ini_trans, max_trans, initial_extent, 
next_extent, min_extent, max_extent, pct_increase, FREELISTS, 
freelist_groups, LOGGING, BUFFER_POOL, num_rows, blocks, 
empty_blocks, avg_space, chain_cnt, avg_row_len, sample_size, 
last_analyzed 
FROM dba_tab_partitions 
--WHERE table_name = :tname AND table_owner = :towner 
ORDER BY partition_position 12、查看还没提交的事务 
select * from v$locked_object; 
select * from v$transaction; 13、查找object为哪些进程所用 
select 
p.spid, 
s.sid, 
s.serial# serial_num, 
s.username user_name, 
a.type object_type, 
s.osuser os_user_name, 
a.owner, 
a.object object_name, 
decode(sign(48 - command), 
1, 
to_char(command), 'Action Code #' || to_char(command) ) action, 
p.program oracle_process, 
s.terminal terminal, 
s.program program, 
s.status session_status 
from v$session s, v$access a, v$process p 
where s.paddr = p.addr and 
s.type = 'USER' and 
a.sid = s.sid and 
a.object='SUBSCRIBER_ATTR' 
order by s.username, s.osuser 14、回滚段查看 
select rownum, sys.dba_rollback_segs.segment_name Name, v$rollstat.extents 
Extents, v$rollstat.rssize Size_in_Bytes, v$rollstat.xacts XActs, 
v$rollstat.gets Gets, v$rollstat.waits Waits, v$rollstat.writes Writes, 
sys.dba_rollback_segs.status status from v$rollstat, sys.dba_rollback_segs, 
v$rollname where v$rollname.name(+) = sys.dba_rollback_segs.segment_name and 
v$rollstat.usn (+) = v$rollname.usn order by rownum 15、耗资源的进程（top session） 
select s.schemaname schema_name, decode(sign(48 - command), 1, 
to_char(command), 'Action Code #' || to_char(command) ) action, status 
session_status, s.osuser os_user_name, s.sid, p.spid , s.serial# serial_num, 
nvl(s.username, '[Oracle process]') user_name, s.terminal terminal, 
s.program program, st.value criteria_value from v$sesstat st, v$session s , v$process p 
where st.sid = s.sid and st.statistic# = to_number('38') and ('ALL' = 'ALL' 
or s.status = 'ALL') and p.addr = s.paddr order by st.value desc, p.spid asc, s.username asc, s.osuser asc 16、查看锁（lock）情况 
select /*+ RULE */ ls.osuser os_user_name, ls.username user_name, 
decode(ls.type, 'RW', 'Row wait enqueue lock', 'TM', 'DML enqueue lock', 'TX', 
'Transaction enqueue lock', 'UL', 'User supplied lock') lock_type, 
o.object_name object, decode(ls.lmode, 1, null, 2, 'Row Share', 3, 
'Row Exclusive', 4, 'Share', 5, 'Share Row Exclusive', 6, 'Exclusive', null) 
lock_mode, o.owner, ls.sid, ls.serial# serial_num, ls.id1, ls.id2 
from sys.dba_objects o, ( select s.osuser, s.username, l.type, 
l.lmode, s.sid, s.serial#, l.id1, l.id2 from v$session s, 
v$lock l where s.sid = l.sid ) ls where o.object_id = ls.id1 and o.owner 
<> 'SYS' order by o.owner, o.object_name 17、查看等待（wait）情况 
SELECT v$waitstat.class, v$waitstat.count count, SUM(v$sysstat.value) sum_value 
FROM v$waitstat, v$sysstat WHERE v$sysstat.name IN ('db block gets', 
'consistent gets') group by v$waitstat.class, v$waitstat.count 18、查看sga情况 
SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC 19、查看catched object 
SELECT owner, name, db_link, namespace, 
type, sharable_mem, loads, executions, 
locks, pins, kept FROM v$db_object_cache 20、查看V$SQLAREA 
SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS, 
VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS, 
USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS, 
BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA 21、查看object分类数量 
select decode (o.type#,1,'INDEX' , 2,'TABLE' , 3 , 'CLUSTER' , 4, 'VIEW' , 5 , 
'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) object_type , count(*) quantity from 
sys.obj$ o where o.type# > 1 group by decode (o.type#,1,'INDEX' , 2,'TABLE' , 3 
, 'CLUSTER' , 4, 'VIEW' , 5 , 'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) union select 
'COLUMN' , count(*) from sys.col$ union select 'DB LINK' , count(*) from 22、按用户查看object种类 
select u.name schema, sum(decode(o.type#, 1, 1, NULL)) indexes, 
sum(decode(o.type#, 2, 1, NULL)) tables, sum(decode(o.type#, 3, 1, NULL)) 
clusters, sum(decode(o.type#, 4, 1, NULL)) views, sum(decode(o.type#, 5, 1, 
NULL)) synonyms, sum(decode(o.type#, 6, 1, NULL)) sequences, 
sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1)) 
others from sys.obj$ o, sys.user$ u where o.type# >= 1 and u.user# = 
o.owner# and u.name <> 'PUBLIC' group by u.name order by 
sys.link$ union select 'CONSTRAINT' , count(*) from sys.con$ 23、有关connection的相关信息 
1）查看有哪些用户连接 
select s.osuser os_user_name, decode(sign(48 - command), 1, to_char(command), 
'Action Code #' || to_char(command) ) action, p.program oracle_process, 
status session_status, s.terminal terminal, s.program program, 
s.username user_name, s.fixed_table_sequence activity_meter, '' query, 
0 memory, 0 max_memory, 0 cpu_usage, s.sid, s.serial# serial_num 
from v$session s, v$process p where s.paddr=p.addr and s.type = 'USER' 
order by s.username, s.osuser 
2）根据v.sid查看对应连接的资源占用等情况 
select n.name, 
v.value, 
n.class, 
n.statistic# 
from v$statname n, 
v$sesstat v 
where v.sid = 71 and 
v.statistic# = n.statistic# 
order by n.class, n.statistic# 
3）根据sid查看对应连接正在运行的sql 
select /*+ PUSH_SUBQ */ 
command_type, 
sql_text, 
sharable_mem, 
persistent_mem, 
runtime_mem, 
sorts, 
version_count, 
loaded_versions, 
open_versions, 
users_opening, 
executions, 
users_executing, 
loads, 
first_load_time, 
invalidations, 
parse_calls, 
disk_reads, 
buffer_gets, 
rows_processed, 
sysdate start_time, 
sysdate finish_time, 
'>' || address sql_address, 
'N' status 
from v$sqlarea 
where address = (select sql_address from v$session where sid = 71) 24、查询表空间使用情况select a.tablespace_name "表空间名称", 
100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "占用率(%)", 
round(a.bytes_alloc/1024/1024,2) "容量(M)", 
round(nvl(b.bytes_free,0)/1024/1024,2) "空闲(M)", 
round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)", 
Largest "最大扩展段(M)", 
to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') "采样时间" 
from (select f.tablespace_name, 
sum(f.bytes) bytes_alloc, 
sum(decode(f.autoextensible,'YES',f.maxbytes,'NO',f.bytes)) maxbytes 
from dba_data_files f 
group by tablespace_name) a, 
(select f.tablespace_name, 
sum(f.bytes) bytes_free 
from dba_free_space f 
group by tablespace_name) b, 
(select round(max(ff.length)*16/1024,2) Largest, 
ts.name tablespace_name 
from sys.fet$ ff, sys.file$ tf,sys.ts$ ts 
where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts# 
group by ts.name, tf.blocks) c 
where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name 25、 查询表空间的碎片程度 
select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name 
having count(tablespace_name)>10; alter tablespace name coalesce; 
alter table name deallocate unused; create or replace view ts_blocks_v as 
select tablespace_name,block_id,bytes,blocks,'free space' segment_name from dba_free_space 
union all 
select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents; select * from ts_blocks_v; 
select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space 
group by tablespace_name;