合 LOW_VALUE、HIGH_VALUE、ENDPOINT_VALUE的转换--UTL_RAW、HEXSTR、DBMS_STATS.CONVERT_RAW_VALUE的使用

 

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目录

    直方图ENDPOINT_VALUE转换：

    首先准备基础表：
    CREATE TABLE T_ST_20170605_LHR(ID NUMBER,STR VARCHAR2(30));
    INSERT INTO T_ST_20170605_LHR SELECT ROWNUM ID,1 STR FROM DUAL CONNECT BY LEVEL<=10001;
    UPDATE T_ST_20170605_LHR T SET T.STR=6 WHERE T.ID=10001;
    EXEC DBMS_STATS.GATHER_TABLE_STATS(USER,'T_ST_20170605_LHR',CASCADE=>TRUE,METHOD_OPT=>'FOR COLUMNS STR SIZE 2');
    查看直方图信息：
    LHR@orclasm > COL COLUMN_NAME FORMAT A15
    LHR@orclasm > SELECT D.COLUMN_NAME,D.NUM_DISTINCT,D.NUM_NULLS,D.NUM_BUCKETS,D.HISTOGRAM FROM DBA_TAB_COL_STATISTICS D WHERE D.TABLE_NAME = 'T_ST_20170605_LHR';

    COLUMN_NAME NUM_DISTINCT NUM_NULLS NUM_BUCKETS HISTOGRAM

    STR 2 0 2 FREQUENCY
    LHR@orclasm > SELECT TABLE_NAME,COLUMN_NAME,ENDPOINT_VALUE,ENDPOINT_NUMBER FROM DBA_TAB_HISTOGRAMS WHERE TABLE_NAME='T_ST_20170605_LHR';

    TABLE_NAME COLUMN_NAME ENDPOINT_VALUE ENDPOINT_NUMBER

    T_ST_20170605_LHR STR 2.5442E+35 10000
    T_ST_20170605_LHR STR 2.8038E+35 10001
    这里的ENDPOINT_VALUE值需要去转换，字符‘1’的16进制的dump值为0x31，字符‘6’的16进制的dump值为0x36，
    LHR@orclasm > SELECT DUMP('1',16),DUMP('6',16) FROM DUAL;

    DUMP('1',16) DUMP('6',16)

    Typ=96 Len=1: 31 Typ=96 Len=1: 36
    将0x31右边补0一直补到15个字节（共30位），再将其转换为10进制数，0x36类似，如下所示：
    LHR@orclasm > SELECT TO_NUMBER('310000000000000000000000000000','XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX') C1,TO_NUMBER('360000000000000000000000000000','XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX') C2 FROM DUAL;

    2.5442E+35 2.8038E+35
    可以看到转换后的结果和之前查询出来的结果一致。为了方便转换给出如下函数：
    CREATE OR REPLACE FUNCTION HEXSTR(P_NUMBER IN NUMBER) RETURN VARCHAR2 AS
    L_STR LONG := TO_CHAR(P_NUMBER, 'fm' || RPAD('x', 50, 'x'));
    L_RETURN VARCHAR2(4000);
    BEGIN
    WHILE (L_STR IS NOT NULL) LOOP
    L_RETURN := L_RETURN || CHR(TO_NUMBER(SUBSTR(L_STR, 1, 2), 'xx'));
    L_STR := SUBSTR(L_STR, 3);
    END LOOP;

    RETURN(SUBSTR(L_RETURN, 1, 6));
    END;
    再次查询：
    LHR@orclasm > COL ENDPOINT_VALUE2 FORMAT A15
    LHR@orclasm > SELECT TABLE_NAME,COLUMN_NAME,ENDPOINT_VALUE,ENDPOINT_NUMBER,HEXSTR(ENDPOINT_VALUE) ENDPOINT_VALUE2 FROM DBA_TAB_HISTOGRAMS WHERE TABLE_NAME='T_ST_20170605_LHR';

    TABLE_NAME COLUMN_NAME ENDPOINT_VALUE ENDPOINT_NUMBER ENDPOINT_VALUE2

    T_ST_20170605_LHR STR 2.5442E+35 10000 1
    T_ST_20170605_LHR STR 2.8038E+35 10001 6

    列统计信息LOW_VALUE、HIGH_VALUE的转换：

    使用DBMS_STATS.CONVERT_RAW_VALUE或UTL_RAW.CAST_TO_NUMBER、UTL_RAW.CAST_TO_VARCHAR2等。

    点击(此处)折叠或打开

    1. CREATE OR REPLACE FUNCTION FUN_DISPLAY_RAW_LHR(P_RAWVAL RAW,
    2. ​ P_TYPE VARCHAR2)
    3. RETURN VARCHAR2 IS
    4. V_NUMBER NUMBER;
    5. V_VARCHAR2 VARCHAR2(32);
    6. V_DATE DATE;
    7. V_NVARCHAR2 NVARCHAR2(32);
    8. V_ROWID ROWID;
    9. V_CHAR CHAR(32);
    10. BEGIN
    11. IF (P_TYPE = 'NUMBER' OR P_TYPE = 'FLOAT') THEN
    12. DBMS_STATS.CONVERT_RAW_VALUE(P_RAWVAL, V_NUMBER);
    13. RETURN TO_CHAR(V_NUMBER);
    14. ELSIF (P_TYPE = 'VARCHAR2') THEN
    15. DBMS_STATS.CONVERT_RAW_VALUE(P_RAWVAL, V_VARCHAR2);
    16. RETURN TO_CHAR(V_VARCHAR2);
    17. ELSIF (P_TYPE = 'DATE' OR P_TYPE LIKE 'TIMESTAMP%') THEN
    18. DBMS_STATS.CONVERT_RAW_VALUE(P_RAWVAL, V_DATE);
    19. RETURN TO_CHAR(V_DATE);
    20. ELSIF (P_TYPE = 'NVARCHAR2') THEN
    21. DBMS_STATS.CONVERT_RAW_VALUE(P_RAWVAL, V_NVARCHAR2);
    22. RETURN TO_CHAR(V_NVARCHAR2);
    23. ELSIF (P_TYPE = 'ROWID') THEN
    24. DBMS_STATS.CONVERT_RAW_VALUE(P_RAWVAL, V_ROWID);
    25. RETURN TO_CHAR(V_ROWID);
    26. ELSIF (P_TYPE = 'CHAR') THEN
    27. DBMS_STATS.CONVERT_RAW_VALUE(P_RAWVAL, V_CHAR);
    28. RETURN TO_CHAR(V_CHAR);
    29. ELSIF (P_TYPE = 'RAW') THEN
    30. RETURN TO_CHAR(P_RAWVAL);
    31. ELSE
    32. RETURN 'UNKNOWN DATATYPE!';
    33. END IF;
    34. EXCEPTION
    35. WHEN OTHERS THEN
    36. RETURN 'ERRORS!';
    37. END FUN_DISPLAY_RAW_LHR;

    点击(此处)折叠或打开

    1. SELECT D.COLUMN_NAME,
    2. ​ D.LOW_VALUE,
    3. ​ D.HIGH_VALUE,
    4. ​ D.DENSITY,
    5. ​ D.NUM_DISTINCT,
    6. ​ D.NUM_NULLS,
    7. ​ D.NUM_BUCKETS,
    8. ​ D.HISTOGRAM,
    9. ​ D.DATA_TYPE,
    10. ​ FUN_DISPLAY_RAW_LHR(D.LOW_VALUE, D.DATA_TYPE) LOW_VALUE1,
    11. ​ FUN_DISPLAY_RAW_LHR(D.HIGH_VALUE, D.DATA_TYPE) HIGH_VALUE1--,
    12. ​ --UTL_RAW.CAST_TO_NUMBER(D.LOW_VALUE) LOW_VALUE2,
    13. ​ --UTL_RAW.CAST_TO_NUMBER(D.HIGH_VALUE) HIGH_VALUE2,
    14. FROM USER_TAB_COLS D
    15. WHERE D.TABLE_NAME = 'T_AA_20170606_LHR';

    ORACLE VERSION 11.2.0.4

    下面是utl_raw包下的所有函数

    1. SQL>desc utl_raw
    3. FUNCTION BIT_AND RETURNS RAW
    4. Argument Name Type In/Out Default?
    6. R1 RAW IN
    7. R2 RAW IN
    9. FUNCTION BIT_COMPLEMENT RETURNS RAW
    10. Argument Name Type In/Out Default?
    12. R RAW IN
    14. FUNCTION BIT_OR RETURNS RAW
    15. Argument Name Type In/Out Default?
    17. R1 RAW IN
    18. R2 RAW IN
    20. FUNCTION BIT_XOR RETURNS RAW
    21. Argument Name Type In/Out Default?
    23. R1 RAW IN
    24. R2 RAW IN
    26. FUNCTION CAST_FROM_BINARY_DOUBLE RETURNS RAW
    27. Argument Name Type In/Out Default?
    29. N BINARY_DOUBLE IN
    30. ENDIANESS BINARY_INTEGER IN DEFAULT
    32. FUNCTION CAST_FROM_BINARY_FLOAT RETURNS RAW
    33. Argument Name Type In/Out Default?
    35. N BINARY_FLOAT IN
    36. ENDIANESS BINARY_INTEGER IN DEFAULT
    38. FUNCTION CAST_FROM_BINARY_INTEGER RETURNS RAW
    39. Argument Name Type In/Out Default?
    41. N BINARY_INTEGER IN
    42. ENDIANESS BINARY_INTEGER IN DEFAULT
    44. FUNCTION CAST_FROM_NUMBER RETURNS RAW
    45. Argument Name Type In/Out Default?
    47. N NUMBER IN
    49. FUNCTION CAST_TO_BINARY_DOUBLE RETURNS BINARY_DOUBLE
    50. Argument Name Type In/Out Default?
    52. R RAW IN
    53. ENDIANESS BINARY_INTEGER IN DEFAULT
    55. FUNCTION CAST_TO_BINARY_FLOAT RETURNS BINARY_FLOAT
    56. Argument Name Type In/Out Default?
    58. R RAW IN
    59. ENDIANESS BINARY_INTEGER IN DEFAULT
    61. FUNCTION CAST_TO_BINARY_INTEGER RETURNS BINARY_INTEGER
    62. Argument Name Type In/Out Default?
    64. R RAW IN
    65. ENDIANESS BINARY_INTEGER IN DEFAULT
    67. FUNCTION CAST_TO_NUMBER RETURNS NUMBER
    68. Argument Name Type In/Out Default?
    70. R RAW IN
    71. FUNCTION CAST_TO_NVARCHAR2 RETURNS NVARCHAR2
    72. Argument Name Type In/Out Default?
    74. R RAW IN
    76. FUNCTION CAST_TO_RAW RETURNS RAW
    77. Argument Name Type In/Out Default?
    79. C VARCHAR2 IN
    81. FUNCTION CAST_TO_VARCHAR2 RETURNS VARCHAR2
    82. Argument Name Type In/Out Default?
    84. R RAW IN
    85. FUNCTION COMPARE RETURNS NUMBER
    86. Argument Name Type In/Out Default?
    88. R1 RAW IN
    89. R2 RAW IN
    90. PAD RAW IN DEFAULT
    92. FUNCTION CONCAT RETURNS RAW
    93. Argument Name Type In/Out Default?
    95. R1 RAW IN DEFAULT
    96. R2 RAW IN DEFAULT
    97. R3 RAW IN DEFAULT
    98. R4 RAW IN DEFAULT
    99. R5 RAW IN DEFAULT
    100. R6 RAW IN DEFAULT
    101. R7 RAW IN DEFAULT
    102. R8 RAW IN DEFAULT
    103. R9 RAW IN DEFAULT
    104. R10 RAW IN DEFAULT
    105. R11 RAW IN DEFAULT
    106. R12 RAW IN DEFAULT
    108. FUNCTION CONVERT RETURNS RAW
    109. Argument Name Type In/Out Default?
    111. R RAW IN
    112. TO_CHARSET VARCHAR2 IN
    113. FROM_CHARSET VARCHAR2 IN
    115. FUNCTION COPIES RETURNS RAW
    116. Argument Name Type In/Out Default?
    118. R RAW IN
    119. N NUMBER IN
    120. FUNCTION LENGTH RETURNS NUMBER
    121. Argument Name Type In/Out Default?
    123. R RAW IN
    125. FUNCTION OVERLAY RETURNS RAW
    126. Argument Name Type In/Out Default?
    128. OVERLAY_STR RAW IN
    129. TARGET RAW IN
    130. POS BINARY_INTEGER IN DEFAULT
    131. LEN BINARY_INTEGER IN DEFAULT
    132. PAD RAW IN DEFAULT
    133. FUNCTION REVERSE RETURNS RAW
    134. Argument Name Type In/Out Default?
    136. R RAW IN
    138. FUNCTION SUBSTR RETURNS RAW
    139. Argument Name Type In/Out Default?
    141. R RAW IN
    142. POS BINARY_INTEGER IN
    143. LEN BINARY_INTEGER IN DEFAULT
    144. FUNCTION TRANSLATE RETURNS RAW
    145. Argument Name Type In/Out Default?
    147. R RAW IN
    148. FROM_SET RAW IN
    149. TO_SET RAW IN
    151. FUNCTION TRANSLITERATE RETURNS RAW
    152. Argument Name Type In/Out Default?
    154. R RAW IN
    155. TO_SET RAW IN DEFAULT
    156. FROM_SET RAW IN DEFAULT
    157. PAD RAW IN DEFAULT
    159. FUNCTION XRANGE RETURNS RAW
    160. Argument Name Type In/Out Default?
    162. START_BYTE RAW IN DEFAULT
    163. END_BYTE RAW IN DEFAULT

    DBMS_STATS.**CONVERT_RAW_VALUE函数**

    1. SQL> desc dbms_stats
    2. PROCEDURE CONVERT_RAW_VALUE
    3. Argument Name Type In/Out Default?
    5. RAWVAL RAW IN
    6. RESVAL VARCHAR2 OUT
    8. PROCEDURE CONVERT_RAW_VALUE
    9. Argument Name Type In/Out Default?
    11. RAWVAL RAW IN
    12. RESVAL DATE OUT
    14. PROCEDURE CONVERT_RAW_VALUE
    15. Argument Name Type In/Out Default?
    17. RAWVAL RAW IN
    19. RESVAL NUMBER OUT
    20. PROCEDURE CONVERT_RAW_VALUE
    21. Argument Name Type In/Out Default?
    23. RAWVAL RAW IN
    24. RESVAL BINARY_FLOAT OUT
    26. PROCEDURE CONVERT_RAW_VALUE
    27. Argument Name Type In/Out Default?
    29. RAWVAL RAW IN
    30. RESVAL BINARY_DOUBLE OUT


    utl_raw、\    CONVERT_RAW_VALUE**使用在 字符数值比对、统计信息等指标数值转换上。

    下面是简单实验。**

    1. --TABLE存在4个不同类型的字段
    2. SQL> DESC TABLE
    3. Name Null? Type
    5. DIS_NUMBER NOT NULL NUMBER(12)
    6. RSVDC3 VARCHAR2(16)
    7. ORDER_PV NUMBER(12,2)
    8. SALE_DATE DATE
    10. --统计信息收集后，列的统计信息如下。SQL执行计划与索引的使用，会参考统计信息获得的值。
    11. --现在我们主要关注LOW_VALUE,HIGH_VALUE字段的值。
    12. COLUMN_NAME LOW_VALUE HIGH_VALUE
    14. DIS_NUMBER C102 C60A6464646464
    15. RSVDC3 3C6241395166 C40A4D4323
    16. ORDER_PV 3D582C5166 C4400707450B
    17. SALE_DATE 786D0305010101 78C70C04010101

    使用utl_raw.CAST_TO_NUMBER函数获取DIS_NUMBER字段，LOW_VALUE与HIGH_VALUE的值。

    1. SQL> select utl_raw.CAST_TO_NUMBER('C102') low_num,utl_raw.CAST_TO_NUMBER('C60A6464646464') high_num from dual
    3. LOW_NUM HIGH_NUM
    5. ​ 1 99999999999
    7. --同样，可以使用utl_raw.CAST_FROM_NUMBER函数转换成数据库的raw格式。
    9. SQL>select utl_raw.CAST_FROM_NUMBER(1) LOW_VALUE,utl_raw.CAST_FROM_NUMBER(99999999999) HIGH_VALUE from dual
    11. ​ LOW_VALUE HIGH_VALUE
    13. ​ C102 C60A6464646464

    同理，VARCHAR类型的值，也可使用utl_raw.CAST_TO_VARCHAR2

    DATE类型使用dbms_stats.convert_raw_value()函数。

    1. DECLARE
      rv RAW(32) := '786D0305010101';
      dt DATE := NULL;
      BEGIN
      dbms_stats.convert_raw_value(rv, dt);
      dbms_output.put_line('LOW_DATE: '||TO_CHAR(dt, 'YYYY-MM-DD hh24:mi:ss'));
      END;
      /

    2. LOW_DATE: 2009-03-05 00:00:00

    下面自定义函数，利用**dbms_stats.convert_raw_value函数，可快速获得不同类型的真实值。**

    1. CREATE OR REPLACE FUNCTION FUN_DISPLAY_RAW_LHR(P_RAWVAL RAW,

      ​ P_TYPE VARCHAR2)

      RETURN VARCHAR2 IS

      V_NUMBER NUMBER;

      V_VARCHAR2 VARCHAR2(32);

      V_DATE DATE;

      V_NVARCHAR2 NVARCHAR2(32);

      V_ROWID ROWID;

      V_CHAR CHAR(32);

      BEGIN

      IF (P_TYPE = 'NUMBER' OR P_TYPE = 'FLOAT') THEN

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