Oracle-SQL长度限制

    最近遇见一个ORA-01795: maximum number of eXPressions in a list is 1000 错误，才知道In-list有1000个元素的限制；可以使用array bind或者temporary table解决，而且还能绑定变量。[Limit and conversion very long IN list : WHERE x IN ( ,,, ...) ]     再想到SQL的长度是否在SQLPLUS里面还有其他的限制？     Logical Database Limits     SQL Statement Length
     Maximum length of statements
     64 K maximum; particular tools may impose lower limits     9i的文档写的最大64K，其实不正确。     在10g的文档中作了修改 Logical Database Limits     The limit on how long a SQL statement can be depends on many factors, including database configuration, disk space, and memory     仔细想想，我们数据库中 package 几十K有很多，当初都是用sqlplus执行创建的；sqlpplus对日常执行的SQL因该不会有长度限制。     先测试一下使用DBMS_SQL执行很长的SQL语句。     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.     通过dbms_sql.varchar2s数组，可以执行很长的SQL。     再将如上pl/sql产生的SQL使用dbms_output输出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;     这个1M的SQL在sqlplus里完全可以执行。看来，oracle完全支持很长的SQL语句；但该sql会占用很多share pool空间,因此不提倡经常执行。     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