版本:11.2.0.2.0與數字相比,Pls_integer值需要「少」存儲。如何驗證?
我想驗證後續的說法,我在手冊中再次閱讀:
的PLS_INTEGER數據類型有過許多這樣的 優勢數據類型 和NUMBER亞型:
PLS_INTEGER values require less storage.
我正在尋找有效使用的字節。
我知道Oracle內置的數據類型和PL/SQL數據類型。 我的文檔中再次讀取特定章節:
我查看了一些有用的功能:visze,dump(依此類推:長度,LENGTHB)。 我在這裏和其他論壇/博客上搜索過,即使它看起來是一個明顯的東西,但我有點卡住了。
我的虛擬程序(visize功能不會爲PLS_INTEGER表現出任何有效的值,因爲下面在他的回答由託尼·安德魯斯所示的理由(請注意13/07/11)
create or replace procedure TestSize
(
testPlsInteger in pls_integer
,testNumber in number
) is
sizePlsInteger pls_integer;
sizeNumber pls_integer;
FORMAT_DIM constant pls_integer := 15;
begin
select vsize(testPlsInteger), vsize(testNumber)
into sizePlsInteger, sizeNumber
from dual;
dbms_output.put_line('number:' || rpad(testPlsInteger, FORMAT_DIM)
||' PLS_INTEGER SIZE:' || rpad(sizePlsInteger, FORMAT_DIM)
|| ' NUMBER SIZE:' || sizeNumber);
end;
測試
begin
TestSize(2147483647, 2147483647);
TestSize(1, 1);
TestSize(1000000, 1000000);
TestSize(12345678, 12345678);
end;
個結果
number:2147483647 PLS_INTEGER SIZE:6 NUMBER SIZE:6
number:1 PLS_INTEGER SIZE:2 NUMBER SIZE:2
number:1000000 PLS_INTEGER SIZE:2 NUMBER SIZE:2
number:12345678 PLS_INTEGER SIZE:5 NUMBER SIZE:5
- 增加13/07/2011
>>>>>>>>> NEW節中的文檔:
The PLS_INTEGER data type has these advantages over the NUMBER data type and NUMBER subtypes: PLS_INTEGER values require less storage.
和
The PLS_INTEGER data type stores signed integers in the range -2,147,483,648 through 2,147,483,647, represented in 32 bits.
- 文檔斷言 「PLS_INTEGER值需要少存儲」 並非總是如此。
應該是真的,數字數據類型應該比pls_integer需要更多的空間。 使用pls_integer大小的常量(類似於doc的32位)重寫前面的過程,我們可以在下面看到它不是真的。
我想這是由於數據類型「數字」
- 的內部表示但OP是「如何驗證」
使用「大 「建議由給出託尼安德魯斯,並加載兩個不同大小的數組(pls_integer和數字),似乎是:
- 使用需要不同/等於存儲不同數目(先前提到的過程「TestSize」的輸出)
- 使用VARRAY實現在PL/SQL陣列
- 測試不同尺寸爲這些陣列10 000, 100 000
- 100,000個數字的大數組需要比pls_integer更多的空間。
PS顯然,這種方法是不完全準確的(像託尼在他的帖子中寫道),並與我的虛擬程序「TestSize」的輸出衝突,提供的方法來計算數字「TestSize」中的大小(vsize爲數字)是正確的!
最後,我很少在我的生產代碼中使用超過100/200元素的陣列,只是避免超負荷PGA。 而對於這個尺寸的疑問依然存在!
其他研究我不得不去發現這個「oracle」,這超出了我的理解;但爲此我寫了這個問題! :-)
步驟使用新的 「Testsize」 程序。
文檔斷言「PLS_INTEGER值要求減去存儲」並非總是如此。
create or replace procedure TestSize
(
testNumber in number
) is
sizeNumber pls_integer;
SIZE_PLS_INTEGER constant pls_integer:= 4; -- always 32 bits(4 bytes)
FORMAT_DIM constant pls_integer := 15;
FORMAT_MINOR constant varchar2(1) := '<';
FORMAT_EQUAL constant varchar2(1) := '=';
begin
select vsize(testNumber)
into sizeNumber
from dual;
dbms_output.put_line('number:' || rpad(testNumber, FORMAT_DIM)
||' PLS_INTEGER SIZE:'
|| case when (SIZE_PLS_INTEGER<sizeNumber) then
rpad(SIZE_PLS_INTEGER, FORMAT_DIM,FORMAT_MINOR)
when (SIZE_PLS_INTEGER=sizeNumber) then
rpad(SIZE_PLS_INTEGER, FORMAT_DIM,FORMAT_EQUAL)
else rpad(SIZE_PLS_INTEGER, FORMAT_DIM)
end
|| ' NUMBER SIZE:'
|| case when (sizeNumber<SIZE_PLS_INTEGER) then
rpad(sizeNumber,FORMAT_DIM,FORMAT_MINOR)
else rpad(sizeNumber,FORMAT_DIM)
end);
end TestSize;
測試
begin
TestSize(2147483647);
TestSize(1);
TestSize(10);
TestSize(100);
TestSize(1000);
TestSize(1000);
TestSize(100000);
TestSize(1000000);
TestSize(10000000);
TestSize(10000000);
TestSize(100000000);
TestSize(1000000000);
TestSize(1000000000);
TestSize(90000000);
TestSize(9923);
TestSize(99232);
TestSize(555555);
TestSize(12345);
TestSize(1234);
TestSize(1000001);
TestSize(20000000000);
TestSize(12345678);
TestSize(12345678);
end;
結果
number:2147483647 PLS_INTEGER SIZE:4<<<<<<<<<<<<<< NUMBER SIZE:6
number:1 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:10 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:100 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:1000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:1000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:100000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:1000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:10000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:10000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:100000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:1000000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:1000000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:90000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:9923 PLS_INTEGER SIZE:4 NUMBER SIZE:3<<<<<<<<<<<<<<
number:99232 PLS_INTEGER SIZE:4============== NUMBER SIZE:4
number:555555 PLS_INTEGER SIZE:4============== NUMBER SIZE:4
number:12345 PLS_INTEGER SIZE:4============== NUMBER SIZE:4
number:1234 PLS_INTEGER SIZE:4 NUMBER SIZE:3<<<<<<<<<<<<<<
number:1000001 PLS_INTEGER SIZE:4<<<<<<<<<<<<<< NUMBER SIZE:5
number:20000000000 PLS_INTEGER SIZE:4 NUMBER SIZE:2<<<<<<<<<<<<<<
number:12345678 PLS_INTEGER SIZE:4<<<<<<<<<<<<<< NUMBER SIZE:5
number:12345678 PLS_INTEGER SIZE:4<<<<<<<<<<<<<< NUMBER SIZE:5
- 的OP是「如何驗證 「
使用」 TestSize2 「偉大」由**託尼·安德魯斯
啞過程給出的建議「
create or replace procedure testSize2
(
testNum in pls_integer
,maxDim in pls_integer
,secondsToWait in pls_integer
) is
type TPlsIntegers is varray(100000) of pls_integer;
type TNumbers is varray(100000) of number;
pls TPlsIntegers := TPlsIntegers();
numbers TNumbers := TNumbers();
MODULE constant varchar2(20) := 'TestSize2';
PLS_ACTION constant varchar2(20) := 'pls_integer';
NUMBER_ACTION constant varchar2(20) := 'number';
SEP constant varchar2(3) := ' - ';
begin
dbms_application_info.set_action(action_name => PLS_ACTION||SEP||testNum ||SEP||maxDim);
pls.extend(maxDim);
for cont in 1 .. maxDim
loop
pls(cont) := testNum;
end loop;
dbms_lock.sleep(seconds => secondsToWait);
-- check pga with query
dbms_application_info.set_action(action_name => NUMBER_ACTION||SEP||testNum ||SEP||maxDim);
numbers.extend(maxDim);
for cont in 1 .. maxDim
loop
numbers(cont) := testNum;
end loop;
-- check pga with query
DBMS_LOCK.sleep(secondsToWait);
end;
測試
declare
MAX_TO_WAIT constant pls_integer := 3;
MODULE constant varchar2(30) := 'testSize2';
begin
debug.disable;
dbms_application_info.set_module(MODULE, action_name => '');
testSize2(testNum => 90000000, secondsToWait => MAX_TO_WAIT, maxDim => 100);
testSize2(testNum => 90000000, secondsToWait => MAX_TO_WAIT, maxDim => 10000); --10 000
testSize2(testNum => 90000000, secondsToWait => MAX_TO_WAIT, maxDim => 100000); --100 000
testSize2(testNum => 12345, secondsToWait => MAX_TO_WAIT, maxDim => 10000); --10 000
testSize2(testNum => 12345, secondsToWait => MAX_TO_WAIT, maxDim => 100000); --100 000
testSize2(testNum => 2147483647, secondsToWait => MAX_TO_WAIT, maxDim => 100);
testSize2(testNum => 2147483647, secondsToWait => MAX_TO_WAIT, maxDim => 10000); --10 000
testSize2(testNum => 2147483647, secondsToWait => MAX_TO_WAIT, maxDim => 100000); --100 000*\*\*/
dbms_application_info.set_action(action_name => 'END');
end;
查詢監視PGA
select vsst.sid || ',' || vses.serial# username, vsst.value,vses.MODULE,vses.ACTION
from v$sesstat vsst, v$statname vstt, v$session vses
where vstt.statistic# = vsst.statistic#
and vsst.sid = vses.sid
and vstt.name = 'session pga memory'
and vses.username = 'HR'
and vses.MODULE = 'testSize2'
Annoted結果
pls_integer number dif
-- size size size
-- n=90000000 DIM aRRAY= 100 528612 594148< DIF= 65536
-- n=90000000 DIM aRRAY= 10000 725220 1118436< DIF= 393216
-- n=90000000 DIM aRRAY= 100000 2101476 5771492> DIF= 3670016
-- n=12345 DIM aRRAY= 10000 921828 1380580< DIF= 458752
-- n=12345 DIM aRRAY= 100000 2101476 5771492> DIF= 3670016
-- n=2147483647 DIM aRRAY= 100 790756 856292 < DIF= 65536
-- n=2147483647 DIM aRRAY= 10000 921828 1380580< DIF= 458752
-- n=2147483647 DIM aRRAY= 100000 2101476 5771492> DIF= 3670016
新增欄目13/07/2011 – zep