最近遇見一個ORA-01795: maximum number of eXPRessions in a list is 1000 錯誤，才知道In-list有1000個元素的限制；可以使用array bind或者temporary table解決，而且還能綁定變量。[Limit and conversion very long IN list : WHERE x IN ( ,,, ...) ] 再想到SQL的長度是否在SQLPLUS里面還有其他的限制？ Logical Database Limits SQL Statement Length
Maximum length of statements
64 K maximum; particular tools may impose lower limits 9i的文檔寫的最大64K，其實不正確。 在10g的文檔中作了修改 Logical Database Limits The limit on how long a SQL statement can be depends on many factors, including database configuration, disk space, and memory 仔細想想，我們數據庫中 package 幾十K有很多，當初都是用sqlplus執行創建的；sqlpplus對日常執行的SQL因該不會有長度限制。 先測試一下使用DBMS_SQL執行很長的SQL語句。 SQL> declare
2 l_stmt dbms_sql.varchar2s;
l_cursor integer default dbms_sql.open_cursor;
l_rows number default 0;
3 4 5 l_length number := 0;
6 begin
7 l_stmt(1) := 'select 1 c1';
8 for i in 2 .. 15000
9 loop
10 l_stmt(i) := ', 1 c' i;
11 end loop;
12 l_stmt(15000) := 'from dual';
13 for i in l_stmt.first .. l_stmt.last
14 loop
15 l_length := l_length + length(l_stmt(i));
16 end loop;
17 dbms_output.put_line( 'length = ' l_length );
18 dbms_sql.parse( c => l_cursor,
19 statement => l_stmt,
20 lb => l_stmt.first,
21 ub => l_stmt.last,
22 lfflg => TRUE,
23 language_flag => dbms_sql.native );
25 l_rows := dbms_sql.execute(l_cursor);
26 dbms_sql.close_cursor( l_cursor );
27 end;
28 /
length = 138898 PL/SQL procedure sUCcessfully completed. 通過dbms_sql.varchar2s數組，可以執行很長的SQL。 再將如上pl/sql產生的SQL使用dbms_output輸出longSQL.sql. SQL> host ls -l longSQL.sql
-rw-r--r-- 1 Oracle dba 1215082 Dec 4 05:19 longSQL.sql
SQL> host head longSQL.sql
select 1 c1
, 1 c2
........................... SQL> host tail longSQL.sql
................
, 1 c14999
, 1 c15000
from dual; 這個1M的SQL在sqlplus里完全可以執行。看來，oracle完全支持很長的SQL語句；但該sql會占用很多share pool空間,因此不提倡經常執行。 SQL> select sql_text, SHARABLE_MEM,PERSISTENT_MEM,RUNTIME_MEM from v$sql where sql_text like '%, 1 c2%'; SQL_TEXT
--------------------------------------------------------------------------
SHARABLE_MEM PERSISTENT_MEM RUNTIME_MEM
------------ -------------- -----------
select 1 c1 , 1 c2 , 1 c3 , 1 c4 , 1 c5 , 1 c6 , 1 c7 , 1 c8 , 1 c9 , 1 c10 , 1
c11 , 1 c12 , 1 c13 , 1 c14 , 1 c15 , 1 c16 , 1 c17 , 1 c18 , 1 c19 , 1 , 1 .............................................................................................
1978774 780448 241252
