I am working on Oracle 11G.
One of my Materialized view has become UNKNOWN (MY_MAT_VW1). You can check the output of the ALL_MVIEWS below.
OWNER | MVIEW_NAME | CONTAINER_NAME | QUERY | QUERY_LEN | UPDATABLE | UPDATE_LOG | MASTER_ROLLBACK_SEG | MASTER_LINK | REWRITE_ENABLED | REWRITE_CAPABILITY | REFRESH_MODE | REFRESH_METHOD | BUILD_MODE | FAST_REFRESHABLE | LAST_REFRESH_TYPE | LAST_REFRESH_DATE | STALENESS | AFTER_FAST_REFRESH | UNKNOWN_PREBUILT | UNKNOWN_PLSQL_FUNC | UNKNOWN_EXTERNAL_TABLE | UNKNOWN_CONSIDER_FRESH | UNKNOWN_IMPORT | UNKNOWN_TRUSTED_FD | COMPILE_STATE | USE_NO_INDEX | STALE_SINCE | NUM_PCT_TABLES | NUM_FRESH_PCT_REGIONS | NUM_STALE_PCT_REGIONS
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MY_DB | MY_MAT_VW1 | MY_MAT_VW1 | select.. | 6728 | N | | | | N | GENERAL | DEMAND | COMPLETE | IMMEDIATE | NO | COMPLETE | 14-Nov-16 | UNKNOWN | NA | N | Y | N | N | N | N | VALID | N | 0 | | |
MY_DB | MY_MAT_VW2 | MY_MAT_VW2 | select.. | 7074 | N | | | | N | TEXTMATCH | DEMAND | COMPLETE | IMMEDIATE | NO | COMPLETE | 13-Nov-16 | FRESH | NA | N | N | N | N | N | N | FRESH | N | 0 | 0 | |
The queries for the materialized view contain complex joins between multiple tables, inline views and unions.
As per my understanding (UNKNOWN_PLSQL_FUNC column) I guess there is a PLSQL Function which is causing the staleness to become UNKNOWN. However I am not sure which one.
I tried re-compiling and refreshing it but no luck.
Can anyone provide me some information on how to detect the root cause and make sure it does not become UNKNOWN again.
Also is there any implication of it on the data stored within it?
Below is just a sample I've created to replicate the scenario.
SELECT * FROM ENTITY_T;
ID | ENTITY_TYPE | FIRST_NAME | LAST_NAME | LEGAL_NAME
--------------------------------------------------
1 | INDIVIDUAL | JOHN | LESSEN |
2 | INDIVIDUAL | ROSAN | MEL |
3 | CORP | SIGMA | | SIGMA CORPORATION
--Function to get name base upon type
CREATE OR REPLACE FUNCTION GET_NAME (P_ID IN NUMBER)
RETURN VARCHAR2
DETERMINISTIC
AS
LV_NAME VARCHAR2(200);
BEGIN
SELECT CASE ENTITY_TYPE WHEN 'INDIVIDUAL' THEN FIRST_NAME ||' '|| LAST_NAME
WHEN 'CORP' THEN LEGAL_NAME
ELSE 'NONE'
END INTO LV_NAME
FROM ENTITY_T
WHERE ID=P_ID;
RETURN LV_NAME;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN 'NO ID FOUND';
WHEN OTHERS THEN
RETURN 'OTHER ERROR';
END;
--Materialized view creation
CREATE MATERIALIZED VIEW TEST_MV
AS
SELECT ID,ENTITY_TYPE,GET_NAME(ID) NAME
FROM ENTITY_T;
SELECT MVIEW_NAME,STALENESS,AFTER_FAST_REFRESH,UNKNOWN_PLSQL_FUNC,COMPILE_STATE,STALE_SINCE
FROM ALL_MVIEWS WHERE MVIEW_NAME='TEST_MV';
MVIEW_NAME | STALENESS | AFTER_FAST_REFRESH | UNKNOWN_PLSQL_FUNC | COMPILE_STATE | STALE_SINCE
----------------------------------------------------------------------------------------------
TEST_MV | UNKNOWN | NA | Y | VALID |
The Oracle Issue/Doc ID 757537.1 mentioned by JSapkota states clearly, that this is not a bug, but correct/expected behaviour:
STALENESS of the mview, refering to PL/SQL function is set to UNKOWN
as one cannot determine PL/SQL function changes. Current behaviour is
correct as per the design & code.
I guess using DETERMINISTIC functions instead of the default scope could prevent it.
As per the My Oracle Support this could be a bug(7582462).
As there is no solution to this bug, you have to deal with fact that staleness will show unknown, or not use functions on Materialized View definition.
Reference:DBA_MVIEWS Shows STALENESS Value of UNKNOWN After Refresh (Doc ID 757537.1)
Related
I have been trying to run this piece of code to drop current day's partition from hive a table and for some reason it does not drop the partition from the hive table. Not sure what's worng.
Table Name : prod_db.products
desc:
+----------------------------+-----------------------+-----------------------+--+
| col_name | data_type | comment |
+----------------------------+-----------------------+-----------------------+--+
| name | string | |
| cost | double | |
| load_date | string | |
| | NULL | NULL |
| # Partition Information | NULL | NULL |
| # col_name | data_type | comment |
| | NULL | NULL |
| load_date | string | |
+----------------------------+-----------------------+-----------------------+--+
## I am using the following code
SET hivevar:current_date=current_date();
ALTER TABLE prod_db.products DROP PARTITION(load_date='${current_date}');
Before and After picture of partitions:
+-----------------------+--+
| partition |
+-----------------------+--+
| load_date=2022-04-07 |
| load_date=2022-04-11 |
| load_date=2022-04-18 |
| load_date=2022-04-25 |
+-----------------------+--+
It runs without any error but doesn't work but won't drop the partition. Table is internal/managed.
I tried different ways mentioned on stack but it is just not working for me.
Help.
You dont need to set a variable. You can directly drop using direct sql.
Alter table prod_db.products
drop partition (load_date= current_date());
We were facing some issues with execution plans while accessing remote database objects with dblink. Here is the query itself run on the remote database:
select --+ index_desc (d DAY_OPERATIONAL_PK)
d.oper_day
from day_operational d
where rownum = 1
The plan for this query is the following :
Plan Hash Value : 2761870770
---------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Time |
---------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 8 | 2 | 00:00:01 |
| * 1 | COUNT STOPKEY | | | | | |
| 2 | INDEX FULL SCAN DESCENDING | DAY_OPERATIONAL_PK | 1 | 8 | 2 | 00:00:01 |
---------------------------------------------------------------------------------------------
This one works correct that is it returns the last operational day. In this case 14.09.2021. However if execute this exact same query from other database connecting to this one via dblink, wrong results are returned . In this case the first row of the table is returned - 05.09.2009.
Here is the query:
select --+ index_desc (d DAY_OPERATIONAL_PK)
d.oper_day
from day_operational#iabs d
where rownum = 1
The plan generated for this query in local database is the following:
Plan Hash Value :
---------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Time |
---------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT REMOTE | | 1 | 8 | 2 | 00:00:01 |
| * 1 | COUNT STOPKEY | | | | | |
| 2 | INDEX FAST FULL SCAN | XPKDAY_OPERATIONAL | 1 | 8 | 2 | 00:00:01 |
---------------------------------------------------------------------------------------
As it can be seen, the plan generated when connected via dblink uses full table scan and ignores index_desc hint. How could we enforce oracle to use this index? Tried adding driving_site hint but it didn't help
Sorry for confusions. It occured that index names in local database and remote database are not same and therefore hint was ignoring since there was no index with that name in the remote db. With right index names, both the plan and result were correct
There is a database that contains several views and tables.
I need create a report (documentation of database) with a list of all the fields in these tables indicating the type and, if possible, an indication of the minimum/maximum values and values from first row. For example:
.------------.--------.--------.--------------.--------------.--------------.
| Table name | Column | Type | MinValue | MaxValue | FirstRow |
:------------+--------+--------+--------------+--------------+--------------:
| Table1 | day | date | ‘2010-09-17’ | ‘2016-12-10’ | ‘2016-12-10’ |
:------------+--------+--------+--------------+--------------+--------------:
| Table1 | price | double | 1030.8 | 29485.7 | 6023.8 |
:------------+--------+--------+--------------+--------------+--------------:
| … | | | | | |
:------------+--------+--------+--------------+--------------+--------------:
| TableN | day | date | ‘2014-06-20’ | ‘2016-11-28’ | ‘2016-11-16’ |
:------------+--------+--------+--------------+--------------+--------------:
| TableN | owner | string | NULL | NULL | ‘Joe’ |
'------------'--------'--------'--------------'--------------'--------------'
I think the execution of many queries
SELECT MAX(column_name) as max_value, MIN(column_name) as min_value
FROM table_name
Will be ineffective on the huge tables that are stored in Hadoop.
After reading documentation found an article about "Statistics in Hive"
It seems I must use request like this:
ANALYZE TABLE tablename COMPUTE STATISTICS FOR COLUMNS;
But this command ended with error:
Error while processing statement: FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.ColumnStatsTask
Do I understand correctly that this request add information to the description of the table and not display the result? Will this request work with view?
Please suggest how to effectively and automatically create documentation for the database in HIVE?
i need help with a query, can't get it to work correctly. What i'm trying to achieve is to have a select box displaying the number of records associated with a particular theme, for some theme it works well for some it displays (0) when infact there are 2 records, I'm wondering if someone could help me on this, your help would be greatly appreciated, please see below my actual query + table structure :
SELECT theme.id_theme, theme.theme, calender.start_date,
calender.id_theme1,calender.id_theme2, calender.id_theme3, COUNT(*) AS total
FROM theme, calender
WHERE (YEAR(calender.start_date) = YEAR(CURDATE())
AND MONTH(calender.start_date) > MONTH(CURDATE()) )
AND (theme.id_theme=calender.id_theme1)
OR (theme.id_theme=calender.id_theme2)
OR (theme.id_theme=calender.id_theme3)
GROUP BY theme.id_theme
ORDER BY theme.theme ASC
THEME table
|---------------------|
| id_theme | theme |
|----------|----------|
| 1 | Yoga |
| 2 | Music |
| 3 | Taichi |
| 4 | Dance |
| 5 | Coaching |
|---------------------|
CALENDAR table
|---------------------------------------------------------------------------|
| id_calender | id_theme1 | id_theme2 | id_theme3 | start_date | end_date |
|-------------|-----------|-----------|-----------|------------|------------|
| 1 | 2 | 4 | | 2015-07-24 | 2015-08-02 |
| 2 | 4 | 1 | 5 | 2015-08-06 | 2015-08-22 |
| 3 | 1 | 3 | 2 | 2014-10-11 | 2015-10-28 |
|---------------------------------------------------------------------------|
LISTBOX
|----------------|
| |
| Yoga (1) |
| Music (1) |
| Taichi (0) |
| Dance (2) |
| Coaching (1) |
|----------------|
Thanking you in advance
I think that themes conditions should be into brackets
((theme.id_theme=calender.id_theme1)
OR (theme.id_theme=calender.id_theme2)
OR (theme.id_theme=calender.id_theme3))
Hope this help
I have one table like this (report)
--------------------------------------------------
| user_id | Department | Position | Record_id |
--------------------------------------------------
| 1 | Science | Professor | 1001 |
| 1 | Maths | | 1002 |
| 1 | History | Teacher | 1003 |
| 2 | Science | Professor | 1004 |
| 2 | Chemistry | Assistant | 1005 |
--------------------------------------------------
I'd like to have the following result
---------------------------------------------------------
| user_id | Department+Position |
---------------------------------------------------------
| 1 | Science,Professor;Maths, ; History,Teacher |
| 2 | Science, Professor; Chemistry, Assistant |
---------------------------------------------------------
That means I need to preserve the empty space as ' ' as you can see in the result table.
Now I know how to use LISTAGG function but only for one column. However, I can't exactly figure out how can I do for two columns at the sametime. Here is my query:
SELECT user_id, LISTAGG(department, ';') WITHIN GROUP (ORDER BY record_id)
FROM report
Thanks in advance :-)
It just requires judicious use of concatenation within the aggregation:
select user_id
, listagg(department || ',' || coalesce(position, ' '), '; ')
within group ( order by record_id )
from report
group by user_id
i.e. aggregate the concatentation of department with a comma and position and replace position with a space if it is NULL.