如何在Oracle中计算表大小

Question

习惯（并且可能会被MSSQL破坏），我想知道如何在Oracle 10g中获得表大小。 我用谷歌搜索了所以我现在意识到我可能没有像sp_spaceused那样简单的选项。我得到的潜在答案仍然是大部分时间过时或不起作用。可能是因为我在我正在使用的架构上不是DBA。

有人会有解决方案和建议吗？

Answer 1

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，同时考虑了索引和表中的任何LOB。通常，您有兴趣知道“Purchase Order表占用多少空间，包括任何索引”，而不仅仅是表本身。您可以随时深入了解详细信息。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
;

Answer 2

-- 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，通过收集统计信息更加准确：

exec dbms_utility.analyze_schema(user,'COMPUTE');

Answer 3

首先，我一般会提醒说，收集表统计信息以进行空间分析是一件有潜在危险的事情。收集统计信息可能会更改查询计划，尤其是在DBA已配置使用您的调用未使用的非默认参数的统计信息收集作业的情况下，并且将导致Oracle重新解析使用所讨论的表的查询，这可能是性能击中。如果DBA故意留下一些没有统计信息的表（如果OPTIMIZER_MODE是CHOOSE则通用），收集统计信息可能导致Oracle停止使用基于规则的优化器并开始使用基于成本的优化器来处理一组查询如果在生产中意外地完成，可能是一个主要的性能问题。如果您的统计信息准确无误，则可以直接查询USER_TABLES（或ALL_TABLES或DBA_TABLES），而无需致电GATHER_TABLE_STATS。如果您的统计数据不准确，可能有原因，您不想打扰现状。

其次，与SQL Server sp_spaceused过程最接近的等价物可能是Oracle的DBMS_SPACE包。 Tom Kyte有一个很好的show_space procedure，为这个包提供了一个简单的界面，并打印出类似于sp_spaceused打印出来的信息。

Answer 4

首先，在桌面上收集优化器统计信息（如果还没有）：

begin
   dbms_stats.gather_table_stats('MYSCHEMA','MYTABLE');
end;
/

警告：正如贾斯汀在回答中所说，收集优化统计数据会影响查询优化，不应该在没有适当注意和考虑的情况下完成！

然后从生成的统计信息中查找表占用的块数：

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。

将块数乘以使用的块大小（通常为8KB）以获得消耗的空间 - 例如17块x 8KB = 136KB。

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this AskTom thread

后对上述内容所做的更改

Answer 5

我修改了WW的查询以提供更详细的信息：

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
/

Answer 6

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
    ;

Answer 7

IIRC您需要的表是DBA_TABLES，DBA_EXTENTS或DBA_SEGMENTS和DBA_DATA_FILES。如果您在计算机上没有管理权限，则可以查看表的USER_和ALL_版本。

Answer 8

select segment_name,segment_type,bytes/1024/1024 MB
from dba_segments
where segment_name='TABLENAME' and owner ='OWNERNAME' order by mb desc;

Answer 9

这是WWs答案的变体，它包括上面提到的其他分区和子分区，以及显示TYPE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;

Answer 10

我修改了查询以获取每个表空间的模式大小。

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
;

Answer 11

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
;

Answer 12

取决于“表格大小”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（如果它是分区的话可能是多个表空间，如果你还想考虑表上的索引，可能还有多个表空间）。 表空间通常包含多个表，并且可以分布在多个文件中。

如果您正在估计表格未来增长所需的空间，那么avg_row_len乘以表格中的行数（或表格中预期的行数）将是一个很好的指南。 但是Oracle会在每个块上留出一些空间，部分是为了允许行在更新时“增长”，部分原因是它可能无法在该块上安装另一行（例如，8K块只能容纳2行3K，虽然这将是一个极端的例子，因为3K比大多数行尺寸大很多）。 所以BLOCKS（在USER_TABLES中）可能是一个更好的指南。

但是如果你在表中有200,000行，删除了一半，那么表仍然会“拥有”相同数量的块。它不会释放它们以供其他表使用。 此外，块不会单独添加到表中，而是添加到称为“范围”的组中。因此，表中通常会有EMPTY_BLOCKS（也在USER_TABLES中）。

Answer 13

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

Answer 14

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 ;

Answer 15

基于块大小返回表的原始大小的简单选择，还包括索引

的大小

select table_name，（nvl （（ 选择总和（块） 来自dba_indexes a，dba_segments b 其中a.index_name = b.segment_name   和a.table_name = dba_tables.table_name ），0）+块）* 8192/1024 TotalSize，blocks * 8 tableSize 来自dba_tables 按顺序排列

Answer 16

还有一个选项允许使用连接获得“选择”大小，并将表大小视为选项

-- 1
EXPLAIN PLAN
   FOR
      SELECT
            Scheme.Table_name.table_column1 AS "column1",
            Scheme.Table_name.table_column2 AS "column2",
            Scheme.Table_name.table_column3 AS "column3",
            FROM Scheme.Table_name
       WHERE ;

SELECT * FROM TABLE (DBMS_XPLAN.display);

Answer 17

我有与计算表数据，表索引和blob字段的最后一个相同的变体：

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;

Source