习惯于(可能被)MSSQL破坏,我想知道如何在Oracle 10g中获得表大小。我已经用谷歌搜索了,所以我现在知道我可能没有像sp_spaceused那样简单的选项。不过,我得到的潜在答案大部分时间已经过时或无法正常工作。可能是因为我不是正在使用的架构的DBA。
会有人提供解决方案和/或建议吗?
习惯于(可能被)MSSQL破坏,我想知道如何在Oracle 10g中获得表大小。我已经用谷歌搜索了,所以我现在知道我可能没有像sp_spaceused那样简单的选项。不过,我得到的潜在答案大部分时间已经过时或无法正常工作。可能是因为我不是正在使用的架构的DBA。
会有人提供解决方案和/或建议吗?
Answers:
您可能对此查询感兴趣。它告诉您为每个表分配了多少空间,并考虑了表中的索引和任何LOB。通常,您很想知道“ Purchase Order表占用了多少空间,包括任何索引”,而不仅仅是表本身。您总是可以深入研究细节。请注意,这需要访问DBA_ *视图。
COLUMN TABLE_NAME FORMAT A32
COLUMN OBJECT_NAME FORMAT A32
COLUMN OWNER FORMAT A10
SELECT
owner,
table_name,
TRUNC(sum(bytes)/1024/1024) Meg,
ROUND( ratio_to_report( sum(bytes) ) over () * 100) Percent
FROM
(SELECT segment_name table_name, owner, bytes
FROM dba_segments
WHERE segment_type IN ('TABLE', 'TABLE PARTITION', 'TABLE SUBPARTITION')
UNION ALL
SELECT i.table_name, i.owner, s.bytes
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name
AND s.owner = i.owner
AND s.segment_type IN ('INDEX', 'INDEX PARTITION', 'INDEX SUBPARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name
AND s.owner = l.owner
AND s.segment_type IN ('LOBSEGMENT', 'LOB PARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name
AND s.owner = l.owner
AND s.segment_type = 'LOBINDEX')
WHERE owner in UPPER('&owner')
GROUP BY table_name, owner
HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */
ORDER BY SUM(bytes) desc
;
-- Tables + Size MB
select owner, table_name, round((num_rows*avg_row_len)/(1024*1024)) MB
from all_tables
where owner not like 'SYS%' -- Exclude system tables.
and num_rows > 0 -- Ignore empty Tables.
order by MB desc -- Biggest first.
;
--Tables + Rows
select owner, table_name, num_rows
from all_tables
where owner not like 'SYS%' -- Exclude system tables.
and num_rows > 0 -- Ignore empty Tables.
order by num_rows desc -- Biggest first.
;
注意:这些是估算值,通过收集统计信息可以使估算值更加准确:
exec dbms_utility.analyze_schema(user,'COMPUTE');
null
(num_rows
,avg_row_len
),您需要在通过以下语句进行分析之前ANALYZE TABLE your_table COMPUTE STATISTICS
首先,我通常会警告说,为了进行空间分析而收集表统计信息可能会很危险。收集统计信息可能会更改查询计划,尤其是如果DBA配置了使用您的呼叫未使用的非默认参数的统计信息收集作业,并且会导致Oracle重新解析利用有问题的表的查询,这可能会提高性能。击中。如果DBA故意留下了一些没有统计信息的表(如果您OPTIMIZER_MODE
选择CHOOSE,则很常见),收集统计信息可能会导致Oracle停止使用基于规则的优化器,并开始对一组查询使用基于成本的优化器,这可能是一个主要性能。如果在生产中意外完成,则会头痛。如果您的统计信息准确无误,则可以查询USER_TABLES
(ALL_TABLES
或DBA_TABLES
)而不直接致电GATHER_TABLE_STATS
。如果您的统计数据不准确,则可能是有原因的,并且您不想打扰现状。
其次,与SQL Server sp_spaceused
过程最接近的等效项可能是Oracle的DBMS_SPACE
软件包。Tom Kyte有一个很好的show_space
过程,可以为该程序包提供简单的界面,并打印出与打印出的内容相似的信息sp_spaceused
。
首先,在表格上收集优化器统计信息(如果还没有的话):
begin
dbms_stats.gather_table_stats('MYSCHEMA','MYTABLE');
end;
/
警告:就像贾斯汀在回答中所说的那样,收集优化器统计信息会影响查询优化,如果没有适当的注意和考虑,则不应该这样做!
然后从生成的统计信息中找到表所占用的块数:
select blocks, empty_blocks, num_freelist_blocks
from all_tables
where owner = 'MYSCHEMA'
and table_name = 'MYTABLE';
分配给该表的块总数为块+ empty_blocks + num_freelist_blocks。
blocks是实际包含数据的块数。
将块数乘以使用中的块大小(通常为8KB)即可获得消耗的空间-例如17个块x 8KB = 136KB。
要一次对架构中的所有表执行此操作:
begin
dbms_stats.gather_schema_stats ('MYSCHEMA');
end;
/
select table_name, blocks, empty_blocks, num_freelist_blocks
from user_tables;
注意:阅读此AskTom线程后,对以上内容进行的更改
我修改了WW的查询以提供更多详细信息:
SELECT * FROM (
SELECT
owner, object_name, object_type, table_name, ROUND(bytes)/1024/1024 AS meg,
tablespace_name, extents, initial_extent,
ROUND(Sum(bytes/1024/1024) OVER (PARTITION BY table_name)) AS total_table_meg
FROM (
-- Tables
SELECT owner, segment_name AS object_name, 'TABLE' AS object_type,
segment_name AS table_name, bytes,
tablespace_name, extents, initial_extent
FROM dba_segments
WHERE segment_type IN ('TABLE', 'TABLE PARTITION', 'TABLE SUBPARTITION')
UNION ALL
-- Indexes
SELECT i.owner, i.index_name AS object_name, 'INDEX' AS object_type,
i.table_name, s.bytes,
s.tablespace_name, s.extents, s.initial_extent
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name
AND s.owner = i.owner
AND s.segment_type IN ('INDEX', 'INDEX PARTITION', 'INDEX SUBPARTITION')
-- LOB Segments
UNION ALL
SELECT l.owner, l.column_name AS object_name, 'LOB_COLUMN' AS object_type,
l.table_name, s.bytes,
s.tablespace_name, s.extents, s.initial_extent
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name
AND s.owner = l.owner
AND s.segment_type = 'LOBSEGMENT'
-- LOB Indexes
UNION ALL
SELECT l.owner, l.column_name AS object_name, 'LOB_INDEX' AS object_type,
l.table_name, s.bytes,
s.tablespace_name, s.extents, s.initial_extent
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name
AND s.owner = l.owner
AND s.segment_type = 'LOBINDEX'
)
WHERE owner = UPPER('&owner')
)
WHERE total_table_meg > 10
ORDER BY total_table_meg DESC, meg DESC
/
对于子分区表和索引,我们可以使用以下查询
SELECT owner, table_name, ROUND(sum(bytes)/1024/1024/1024, 2) GB
FROM
(SELECT segment_name table_name, owner, bytes
FROM dba_segments
WHERE segment_type IN ('TABLE', 'TABLE PARTITION', 'TABLE SUBPARTITION')
UNION ALL
SELECT i.table_name, i.owner, s.bytes
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name
AND s.owner = i.owner
AND s.segment_type IN ('INDEX', 'INDEX PARTITION', 'INDEX SUBPARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name
AND s.owner = l.owner
AND s.segment_type = 'LOBSEGMENT'
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name
AND s.owner = l.owner
AND s.segment_type = 'LOBINDEX')
WHERE owner in UPPER('&owner')
GROUP BY table_name, owner
HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */
ORDER BY SUM(bytes) DESC
;
IIRC您需要的表是DBA_TABLES,DBA_EXTENTS或DBA_SEGMENTS和DBA_DATA_FILES。这些表还有USER_和ALL_版本,您可以查看它们是否对计算机没有管理权限。
这是WW答案的一个变体,它包括上面其他建议的分区和子分区,以及一列显示类型的列:表/索引/ LOB等
SELECT
owner, "Type", table_name "Name", TRUNC(sum(bytes)/1024/1024) Meg
FROM
( SELECT segment_name table_name, owner, bytes, 'Table' as "Type"
FROM dba_segments
WHERE segment_type in ('TABLE','TABLE PARTITION','TABLE SUBPARTITION')
UNION ALL
SELECT i.table_name, i.owner, s.bytes, 'Index' as "Type"
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name
AND s.owner = i.owner
AND s.segment_type in ('INDEX','INDEX PARTITION','INDEX SUBPARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes, 'LOB' as "Type"
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name
AND s.owner = l.owner
AND s.segment_type IN ('LOBSEGMENT','LOB PARTITION','LOB SUBPARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes, 'LOB Index' as "Type"
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name
AND s.owner = l.owner
AND s.segment_type = 'LOBINDEX')
WHERE owner in UPPER('&owner')
GROUP BY table_name, owner, "Type"
HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */
ORDER BY SUM(bytes) desc;
我修改了查询以获取每个表空间的架构大小。
SELECT owner,
tablespace_name,
TRUNC (SUM (bytes) / 1024 / 1024) Meg,
ROUND (ratio_to_report (SUM (bytes)) OVER () * 100) Percent
FROM (SELECT tablespace_name, owner, bytes
FROM dba_segments
WHERE segment_type IN
('TABLE', 'TABLE PARTITION', 'TABLE SUBPARTITION')
UNION ALL
SELECT i.tablespace_name, i.owner, s.bytes
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name
AND s.owner = i.owner
AND s.segment_type IN
('INDEX', 'INDEX PARTITION', 'INDEX SUBPARTITION')
UNION ALL
SELECT l.tablespace_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name
AND s.owner = l.owner
AND s.segment_type IN ('LOBSEGMENT', 'LOB PARTITION')
UNION ALL
SELECT l.tablespace_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name
AND s.owner = l.owner
AND s.segment_type = 'LOBINDEX')
WHERE owner IN UPPER ('&owner')
GROUP BY owner, tablespace_name
--HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */
ORDER BY tablespace_name -- desc
;
取决于“表的大小”的含义。表与文件系统上的特定文件无关。一个表将驻留在一个表空间上(如果已分区,则可能有多个表空间;如果您还想考虑该表上的索引,则可能有多个表空间)。一个表空间中通常会有多个表,并且可能分布在多个文件中。
如果您要估算表的未来增长需要多少空间,那么avg_row_len乘以表中的行数(或表中预期的行数)将是一个很好的指南。但是Oracle将在每个块上保留一些空间,部分是为了让行在更新后能“增长”,部分是因为不可能将另一整行容纳在该块上(例如8K块只能容纳2行) 3K,尽管这将是一个极端的例子,因为3K比大多数行的尺寸大得多)。因此(在USER_TABLES中)BLOCKS可能是更好的指南。
但是,如果表中有20万行,删除了其中的一半,则该表仍将“拥有”相同数量的块。它不会释放它们供其他表使用。此外,块不会单独添加到表中,而是以称为“扩展区”的组添加。因此,表中通常会有EMPTY_BLOCKS(也在USER_TABLES中)。
分区表的更正:
SELECT owner, table_name, ROUND(sum(bytes)/1024/1024/1024, 2) GB FROM (SELECT segment_name table_name, owner, bytes FROM dba_segments WHERE segment_type IN ('TABLE', 'TABLE PARTITION', 'TABLE SUBPARTITION') UNION ALL SELECT i.table_name, i.owner, s.bytes FROM dba_indexes i, dba_segments s WHERE s.segment_name = i.index_name AND s.owner = i.owner AND s.segment_type IN ('INDEX', 'INDEX PARTITION', 'INDEX SUBPARTITION') UNION ALL SELECT l.table_name, l.owner, s.bytes FROM dba_lobs l, dba_segments s WHERE s.segment_name = l.segment_name and s.owner = l.owner AND s.segment_type in ('LOBSEGMENT', 'LOB PARTITION', 'LOB SUBPARTITION') UNION ALL SELECT l.table_name, l.owner, s.bytes FROM dba_lobs l, dba_segments s WHERE s.segment_name = l.index_name AND s.owner = l.owner AND s.segment_type = 'LOBINDEX') WHERE owner in UPPER('&owner') GROUP BY table_name, owner HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */ order by sum(bytes) desc ;
我发现这更加准确:
SELECT
owner, table_name, TRUNC(sum(bytes)/1024/1024/1024) GB
FROM
(SELECT segment_name table_name, owner, bytes
FROM dba_segments
WHERE segment_type in ('TABLE','TABLE PARTITION')
UNION ALL
SELECT i.table_name, i.owner, s.bytes
FROM dba_indexes i, dba_segments s
WHERE s.segment_name = i.index_name
AND s.owner = i.owner
AND s.segment_type in ('INDEX','INDEX PARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.segment_name
AND s.owner = l.owner
AND s.segment_type IN ('LOBSEGMENT','LOB PARTITION')
UNION ALL
SELECT l.table_name, l.owner, s.bytes
FROM dba_lobs l, dba_segments s
WHERE s.segment_name = l.index_name
AND s.owner = l.owner
AND s.segment_type = 'LOBINDEX')
---WHERE owner in UPPER('&owner')
GROUP BY table_name, owner
HAVING SUM(bytes)/1024/1024 > 10 /* Ignore really small tables */
ORDER BY SUM(bytes) desc
select segment_name as tablename, sum(bytes/ (1024 * 1024 * 1024)) as tablesize_in_GB
From dba_segments /* if looking at tables not owned by you else use user_segments */
where segment_name = 'TABLE_WHOSE_SIZE_I_WANT_TO_KNOW'
and OWNER = 'WHO OWNS THAT TABLE' /* if user_segments is used delete this line */
group by segment_name ;
我有和最后一个变量相同的变量,用于计算表数据,表索引和Blob字段的段:
CREATE OR REPLACE FUNCTION
SYS.RAZMER_TABLICY_RAW(pNazvanie in varchar, pOwner in varchar2)
return number
is
val number(16);
sz number(16);
begin
sz := 0;
--Calculate size of table data segments
select
sum(t.bytes) into val
from
sys.dba_segments t
where
t.segment_name = upper(pNazvanie)
and
t.owner = upper(pOwner);
sz := sz + nvl(val,0);
--Calculate size of table indexes segments
select
sum(s.bytes) into val
from
all_indexes t
inner join
dba_segments s
on
t.index_name = s.segment_name
where
t.table_name = upper(pNazvanie)
and
t.owner = upper(pOwner);
sz := sz + nvl(val,0);
--Calculate size of table blob segments
select
sum(s.bytes) into val
from
all_lobs t
inner join
dba_segments s on t.segment_name = s.segment_name
where
t.table_name = upper(pNazvanie)
and
t.owner = upper(pOwner);
sz := sz + nvl(val,0);
return sz;
end razmer_tablicy_raw;
来源。