2026-03-12 20:23:15

my/stats_hhist.sql

@@ -0,0 +1,131 @@
+@@myheader.sql
+
+/************************************
+*  INPUT PARAMETERS
+************************************/
+DEFINE tab="&&1"
+DEFINE col="&&2"
+
+UNDEFINE owner
+UNDEFINE table_name
+UNDEFINE col_name
+
+COLUMN  _owner              NEW_VALUE owner            NOPRINT
+COLUMN  _table_name         NEW_VALUE table_name       NOPRINT
+COLUMN  _col_name           NEW_VALUE col_name         NOPRINT
+
+set term off
+SELECT 
+      upper(CASE 
+                    WHEN INSTR('&&tab','.') > 0 THEN 
+                        SUBSTR('&&tab',INSTR('&&tab','.')+1)
+                    ELSE
+                        '&tab'
+            END
+            )
+              "_table_name"
+    , upper(CASE 
+                    WHEN INSTR('&&tab','.') > 0 THEN
+                        UPPER(SUBSTR('&&tab',1,INSTR('&&tab','.')-1))
+                     ELSE
+                          user
+            END
+            )
+                "_owner"
+    , upper('&&col')
+                "_col_name"
+FROM DUAL;
+
+
+
+set term on
+
+PROMPT
+PROMPT *************************************************
+PROMPT *  Historical column histogram values           
+PROMPT *                                               
+PROMPT *  Input Parameters                             
+PROMPT *  - owner               = '&&owner'            
+PROMPT *  - table_name          = '&&table_name'       
+PROMPT *  - col_name            = '&&col_name'         
+PROMPT *************************************************
+
+/* ----------------------------------------------------------------------------------|
+|Author : Mohamed Houri                                                              |
+|Date   : 03/07/2020                                                                 |
+|Scope  : This script gives historical column histogram values                       |
+|          -- I am using sys.WRI$_OPTSTAT_HISTHEAD_HISTORY for this purpose          |      
+|          -- I am only able to say whether, previously, there was HISTOGRAM or not  |
+|          -- I can't show the historical type of Histogram                          |
+|                                                                                    |                                    |
+-------------------------------------------------------------------------------------|*/
+
+col object_name         format a25
+col column_name         format a25
+col last_analyzed       format a20
+col prev_last_analyzed  format a20
+col histogram           format a16
+col prev_histogram      format a16
+WITH sq AS
+    (
+     SELECT
+          object_id
+         ,object_name
+         ,subobject_name
+     FROM
+         dba_objects
+     WHERE
+         object_name    = upper ('&&table_name')
+     AND owner          = upper('&&owner')
+     AND subobject_name IS NULL
+     )
+SELECT
+     object_name
+    ,column_name
+    ,lead(prev_histogram,1,histogram) over (order by last_analyzed) histogram
+    ,last_analyzed
+    ,prev_histogram
+    ,prev_last_analyzed
+FROM
+   (
+     SELECT
+         object_name
+        ,column_name
+        ,(select histogram from all_tab_col_statistics where owner = upper('&&owner') 
+          and table_name = upper('&&table_name') and column_name = upper('&&col_name')) histogram
+        ,last_analyzed
+        ,stat_time prev_last_analyzed
+        ,row_number() over (order by last_analyzed) rn
+        ,case when round(derivedDensity,9)= round(density,9) then 'NONE' else 'HISTOGRAM' end prev_histogram
+     FROM
+        (
+         SELECT
+             object_name
+            ,column_name
+            ,to_char(savtime ,'yyyy-mm-dd hh24:mi:ss')     last_analyzed
+            ,to_char(timestamp# ,'yyyy-mm-dd hh24:mi:ss') stat_time
+            ,density
+            ,1/distcnt derivedDensity
+            ,row_number() over (order by savtime) rn
+            ,lag(case when round(1/distcnt,9) = round(density,9) then 'NONE' else 'HISTOGRAM' end) over(order by savtime) hist_histogram
+         FROM
+            sys.WRI$_OPTSTAT_HISTHEAD_HISTORY
+            INNER JOIN sq ON object_id = obj#
+            INNER JOIN (SELECT 
+                            column_id
+                           ,column_name
+                        FROM
+                            dba_tab_columns
+                        WHERE
+                            column_name = upper('&&col_name')
+                        AND table_name  = upper('&&table_name') 
+                        AND owner       = upper('&&owner')
+                        ) ON intcol# = column_id
+    )
+WHERE
+   rn >= 1 --exlcude/include the very first dbms_stat
+   )
+ORDER BY
+    last_analyzed; 
+
+@@myfooter.sql