четверг, 14 апреля 2016 г.

Work test of DETERMINISTIC function

SQL> set timing off;
SQL> def cnt = 10000000;
SQL> 
SQL> create or replace package detest as
  2    function test1(p in varchar2) return varchar2 DETERMINISTIC;
  3    function test2(p in varchar2) return varchar2 DETERMINISTIC;
  4  end;
  5  /

Package created.

SQL> 
SQL> create or replace package body detest as
  2    vCache varchar2( 2000 );
  3  
  4    function test1(p in varchar2) return varchar2
  5    as
  6    begin
  7      if p = 's' then
  8        return 't';
  9      else
 10        return null;
 11      end if;
 12    end;
 13  
 14    function test2(p in varchar2) return varchar2
 15    as
 16    begin
 17      if p = 's' then
 18        if vCache is null then
 19          select 't' into vCache from ALL_OBJECTS where rownum < 2;
 20        end if;
 21        return vCache;
 22      else
 23        return null;
 24      end if;
 25    end;
 26  
 27  end;
 28  /

Package body created.

SQL> 
SQL> set timing on;
SQL> 
SQL> declare
  2    vDummy varchar2(2000);
  3  begin
  4    for i in 1..&cnt
  5    loop
  6      vDummy := detest.test1('z');
  7      vDummy := detest.test1('s');
  8    end loop;
  9  end;
 10  /
old   4:   for i in 1..&cnt
new   4:   for i in 1..10000000

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.25
SQL> 
SQL> declare
  2    vDummy varchar2(2000);
  3  begin
  4    for i in 1..&cnt
  5    loop
  6      vDummy := detest.test2('z');
  7      vDummy := detest.test2('s');
  8    end loop;
  9  end;
 10  /
old   4:   for i in 1..&cnt
new   4:   for i in 1..10000000

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.39
SQL> 
SQL> set timing off;
SQL> 
SQL> create or replace package detest as
  2    function test1(p in varchar2) return varchar2;
  3    function test2(p in varchar2) return varchar2;
  4  end;
  5  /

Package created.

SQL> 
SQL> set timing on;
SQL> 
SQL> declare
  2    vDummy varchar2(2000);
  3  begin
  4    for i in 1..&cnt
  5    loop
  6      vDummy := detest.test1('z');
  7      vDummy := detest.test1('s');
  8    end loop;
  9  end;
 10  /
old   4:   for i in 1..&cnt
new   4:   for i in 1..10000000

PL/SQL procedure successfully completed.

Elapsed: 00:00:02.77
SQL> 
SQL> declare
  2    vDummy varchar2(2000);
  3  begin
  4    for i in 1..&cnt
  5    loop
  6      vDummy := detest.test2('z');
  7      vDummy := detest.test2('s');
  8    end loop;
  9  end;
 10  /
old   4:   for i in 1..&cnt
new   4:   for i in 1..10000000

PL/SQL procedure successfully completed.

Elapsed: 00:00:03.46
SQL> spool off

пятница, 18 марта 2016 г.

How to generate hierarchy query to string

select listagg(txt) within group (order by rn)
from (
  select
    isn, parentisn, rn,
    shortname ||
    decode(nxtlvl, lvl + 1, '(', '') ||
    decode(nxtlvl, lvl, ',', '') || 
    decode(nxtlvl, lvl + 1, '', lvl, '', ltrim(lpad(')', lvl - nxtlvl, ')'))) txt
  from (
    select t.*, lead(lvl) over(order by rn) nxtlvl
    from (
      select isn, parentisn, shortname, rownum rn, level lvl
      from dicti d
      start with isn = 8167
      connect by prior isn = parentisn
      order siblings by shortname) t))

пятница, 19 февраля 2016 г.

Out SYS_REFCURSOR into console

create or replace PROCEDURE grachevcur(
                            p_refcursor        IN OUT SYS_REFCURSOR
                         )  
    AS
        l_desc          DBMS_SQL.DESC_TAB ;
        l_cols          BINARY_INTEGER ;
        l_cursor        BINARY_INTEGER ;
        v_varchar2      VARCHAR2( 4000 ) ;
        v_number        NUMBER ;
        v_date          DATE ;
        l_data          varchar2( 32767 ) ;
        l_columnValue   VARCHAR2( 32767 ) ;
        l_processedRows Number := 0;
    BEGIN
 
        /* Convert refcursor "parameter" to DBMS_SQL cursor... */
        l_cursor := DBMS_SQL.TO_CURSOR_NUMBER( p_refcursor );
        /* Describe the cursor... */
        DBMS_SQL.DESCRIBE_COLUMNS( l_cursor, l_cols, l_desc );
 
        /* Define columns to be fetched. We're only using V2, NUM, DATE for example...
        for a complete list of the col_types this link is accessible.
        http://download.oracle.com/docs/cd/B10501_01/server.920/a96540/sql_elements2a.htm#45504
        http://forums.oracle.com/forums/thread.jspa?threadID=912475
        if not a usable type, will throw new exception
        */
         FOR i IN 1 .. l_cols LOOP
             IF l_desc(i).col_type = 2 THEN
               DBMS_SQL.DEFINE_COLUMN(l_cursor, i, v_number);
            ELSIF l_desc(i).col_type = 12 THEN
               DBMS_SQL.DEFINE_COLUMN(l_cursor, i, v_date);
            ELSif l_desc(i).col_type = 01 or l_desc(i).col_type = 96 then
               DBMS_SQL.DEFINE_COLUMN(l_cursor, i, v_varchar2, 4000);
            else
                --raise an exception if the user's query contains a datatype not (yet) supported by this procedure
                RAISE_APPLICATION_ERROR(-20000, 'Invalid Data Type for conversion to delimited file. {' || l_desc(i).col_name || '}');
            END IF;
          END LOOP;
 
 
        /* -- print out the column names if desired
             FOR i IN 1 .. l_cols LOOP
                     dbms_output.put_line('** ' || l_desc(i).col_name) ;
             END LOOP;
        */
 
         /* Fetch all data... */
         WHILE DBMS_SQL.FETCH_ROWS(l_cursor) > 0 LOOP
             dbms_output.put_line('LINE: '  || l_processedRows || '');
             FOR i IN 1 .. l_cols LOOP
                 if l_desc(i).col_type = 12 THEN --we are in a date
                    DBMS_SQL.COLUMN_VALUE(l_cursor, i, v_date);
                    v_varchar2 := to_char(v_date , 'dd-MON-yyyy' ) ;
                 elsif  l_desc(i).col_type = 2 THEN --we are in a number
                    DBMS_SQL.COLUMN_VALUE(l_cursor, i, v_number);
                    v_varchar2 := to_char(v_number) ;
                 else --treat it as a string (should be varchar2,char,etc)
                    DBMS_SQL.COLUMN_VALUE(l_cursor, i, v_varchar2);
                    IF v_varchar2 IS NOT NULL THEN
                       v_varchar2 := '"' || v_varchar2 || '"' ;
                       ELSE
                       v_varchar2 := '';
                    END IF ;
                 end if ;
                 dbms_output.put_line('  ' ||l_desc(i).col_name || '=>' || v_varchar2) ;
             END LOOP;
             l_processedRows := l_processedRows + 1 ;
          END LOOP;
 
          dbms_sql.close_cursor(l_cursor);
          dbms_output.put_line('I found and processed  '  || l_processedRows || ' rows .');
 
    END;
/