Rewriting Subquery Within Select Due to Oracle Materialized View Limitation - oracle

Oracle poses a limitation on using a subquery within the select clause when creating a materialized view. When you do so, you receive the error "ORA-22818: subquery expressions not allowed here".
Due to this limitation, I've been struggling to rewrite the query and move the subquery out of the select clause. The query is recursively building a path using parent/child relationships, and I'm trying to also indicate if a particular category is a leaf category by joining the table back to itself and seeing if the record has a child.
SELECT A.PRODUCTCATEGORYID, A.PARENTCATEGORYID, SYS_CONNECT_BY_PATH(A.LABEL, ':') "PATH",
(
SELECT CASE WHEN MAX(PRODUCTCATEGORYID) IS NOT NULL THEN 0 ELSE 1 END
FROM PRODUCT_CATEGORY
WHERE parentcategoryid = A.PRODUCTCATEGORYID
) as "LEAF"
FROM PRODUCT_CATEGORY A
CONNECT BY PRIOR A.PRODUCTCATEGORYID = A.PARENTCATEGORYID
START WITH A.PARENTCATEGORYID IS NULL;
Can anyone point me in the right direction of how I should go about rewriting this so the subquery is not part of the select clause?
Thanks in advance.

You can use the CONNECT_BY_ISLEAF pseudocolumn, which returns 1 if current node is a leaf, and 0 otherwise, so your query should be rewritten like this:
SELECT A.PRODUCTCATEGORYID, A.PARENTCATEGORYID, SYS_CONNECT_BY_PATH(A.LABEL, ':') "PATH",
CONNECT_BY_ISLEAF as "LEAF"
FROM PRODUCT_CATEGORY A
CONNECT BY PRIOR A.PRODUCTCATEGORYID = A.PARENTCATEGORYID
START WITH A.PARENTCATEGORYID IS NULL;
Read more in Oracle's documentation: CONNECT_BY_ISLEAF pseudocolumn

Related

How to retrieve data from 3 tables using sub query oracle SQL

I want to retrieve users name and there responsibility_key where there end_date is null and i want to convert it to (sysdate+1) using nvl but i am only able to retrieve the responsibility_key not the name please help.
The error in the image says "column ambiguously defined". Take a close look. Your last END_DATE could refer to either the u alias or the table from the subquery. Change it to match the rest of your subquery (FIND_USER_GROUPS_DIRECT.END_DATE)
EDIT
Your query is
select u.USER_NAME, d.responsibility_key from FND_USER u,FND_RESPONSIBILITY_VL d
where responsibility_id in(
select responsibility_id from
FND_USER_RESP_GROUPS_DIRECT WHERE END_USER_RESP_GROUPS_DIRECT.END_DATE=nvl(END_DATE,sysdate+1)) and
u.END_DATE=nvl(END_DATE,SYSDATE + 1)
;
The query isn't formatted, which makes it hard to read.
Not all columns are qualified with table name (or aliases), as mentioned in the comments.
The query currently uses an implicit join.
The query is impossible to understand without seeing the table definitions (desc [table_name]).
For points 1 and 2, a properly formatted query will look something like
select u.user_name, d.responsibility_key
from
fnd_user u,
fnd_responsibility_vl d
where
d.responsibility_id in (
select urgd.responsibility_id
from
fnd_user_resp_groups_direct urgd
where
urgd.end_date = nvl(u.end_date, sysdate+1)
) and
u.end_date = nvl(urgd.end_date, sysdate + 1)
;
This makes it easier to read and in addition to this, you can see that without table definitions I guessed (see point 4) as to which tables the end_date column belongs in your query. If I had to guess, so does Oracle. That means you have an ambiguity problem. To fix it, take a close look at the end_date column as it appears in your original query and where you do not prefix it with anything, you need to prefix it with the appropriate alias (after you have aliased all your tables).
For point 3, you can write your query more clearly with an explicit join and by using aliases for all columns. As for the explicit join I have no idea what your tables look like but one possibility is something like
select u.user_name, d.responsibility_key
from fnd_user u
join fnd_responsibility_vl d
on u.id = d.user_id
where
d.responsibility_id in (
select responsibility_id
from fnd_user_resp_groups_direct urgd
where
urgd.end_date = nvl(u.end_date, sysdate+1)
) and
u.end_date = nvl(urgd.end_date, sysdate+1)
;
If you follow these points you will get to the root of the error.

HIve join without common filed

I have the following tables:
Table1:
user_name Url
Rahul www.cric.info.com
ranbir www.rogby.com
sahil www.google.com
banit www.yahoo.com
Table2:
Keyword category
cric sports
footbal sports
google search
I want to search Table1 by matching the keyword in Table2. I can perform the same using case statement and the query works but it is not the right approach because each time I have to add the case statement when I will add new search keyword.
select user_name from table1
case when url like '%cric%' then sports
else 'undefined'
end as category
from table1;
Thanks find the soluntions for this approach. FIrst we need to do the Join and after that we need to filter the record.
select user_name,url,Keyword,catagory from(select table1.user_name,table1.url ,table2.keyword,table2.catagory from table1 left outer join table2)a where a.url like (concat('%',a.phrase,'%')
Not sure about more current versions, but I've run into a similar problem... the primary issue is that Hive only supports equi-join statements... when you apply logic to either side of the join, it has difficulty translating into a Map Reduce function.
The alternative method, if you have a reliably structured field, is that you can create a matching key from the larger field. For example, if you know that you're looking for your keyword to exist in the second position of a dot-delimited URI, you could do something like:
select
Uri
, split(Uri, "\\.")[1] as matchKey
from
Table1
join Table2 on Table2.keyword = Table1.matchKey
;

Oracle ignores hint for index with synonym and 2 views

This is the query i am running:
select /*+ index(V_AMV_PLG_ORDER_HISTORY_200_MS.orders.T0 IDX_ORDER_VERSION_3) */ *
from V_AMV_PLG_ORDER_HISTORY_200_MS
where EXCHANGE_SK = 32 and PRODUCT_SK = 1000169
And it uses a different index than the one i am ordering it to.
As you can see, I am querying from the view V_AMV_PLG_ORDER_HISTORY_200_MS, you can see its sql query here:
V_AMV_PLG_ORDER_HISTORY_200_MS view SQL Query:
SELECT AMV_PERF_PROFILES_FRONTEND.AMV_PLG_GET_SEGMENT(200, orders.ORDER_GLOBAL_DATE_TIME) AS ORDER_DATE_TIME,
SUM(orders.BASE_VOLUME) AS VOLUME,
SUM(orders.BASE_CURR_LIMIT_PRICE*orders.BASE_VOLUME)/SUM(orders.BASE_VOLUME) AS PRICE,
orders.PRODUCT_SK AS PRODUCT_SK,
orders.EXCHANGE_SK AS EXCHANGE_SK,
orders.DIRECTION_CD AS DIRECTION_CD,
orders.AGG_UNIT_CD AS AGG_UNIT_CD,
orders.TRADER_KEY AS EXECUTING_REPRESENTATIVE_KEY,
orders.ACCOUNT_KEY AS ACCOUNT_KEY,
a.BUSINESS_UNIT_CD AS BUSINESS_UNIT_CD
FROM AMV_PERF_PROFILES_FRONTEND.S_AMV_ORDER_VERSION_NEW orders
INNER JOIN AMV_PERF_PROFILES_FRONTEND.S_AMV_ACCOUNT a
ON a.ACCOUNT_KEY = orders.ACCOUNT_KEY
WHERE BASE_VOLUME > 0
GROUP BY AMV_PERF_PROFILES_FRONTEND.AMV_PLG_GET_SEGMENT(200, orders.ORDER_GLOBAL_DATE_TIME),
orders.PRODUCT_SK,
orders.EXCHANGE_SK,
orders.ACCOUNT_KEY,
a.BUSINESS_UNIT_CD,
orders.AGG_UNIT_CD,
orders.TRADER_KEY,
orders.DIRECTION_CD;
He is getting the data using the Synonym S_AMV_ORDER_VERSION_NEW, Which directs to another Scheme, to a view called V_AMV_ORDER_VERSION and refering to it as orders, its sql query here:
V_AMV_ORDER_VERSION view Sql query:
SELECT T1.ENTITY_KEY ,
T2.AGG_UNIT_CD ,
T0.BASE_CURR_LIMIT_PRICE ,
T7.DIRECTION_CD ,
T0.EXCHANGE_SK,
T0.ORDER_LOCAL_DATE_TIME ,
T0.PRODUCT_SK,
T18.ENTITY_KEY ,
T19.ENTITY_KEY ,
T0.NOTIONAL_VALUE2 ,
T0.NOTIONAL_VALUE ,
T0.ORDER_GLOBAL_DATE_TIME ,
T0.BASE_VOLUME ,
T31.TRANSACTION_STATUS_CD ,
T0.ORDER_VERSION_KEY
FROM ETS_UDM_CDS_NEW.ORDER_VERSION T0
LEFT OUTER JOIN ETS_UDM_CDS_NEW.ENTITY T1
ON T0.ACCOUNT_SK = T1.ENTITY_SK
LEFT OUTER JOIN ETS_UDM_CDS_NEW.AGG_UNIT T2
ON T0.AGG_UNIT_SK = T2.ENTITY_SK
LEFT OUTER JOIN ETS_UDM_CDS_NEW.DIRECTION T7
ON T0.DIRECTION_SK = T7.ENTITY_SK
LEFT OUTER JOIN ETS_UDM_CDS_NEW.ENTITY T18
ON T0.LOCAL_TIME_ZONE_SK = T18.ENTITY_SK
LEFT OUTER JOIN ETS_UDM_CDS_NEW.ENTITY T19
ON T0.TRADER_SK = T19.ENTITY_SK
LEFT OUTER JOIN ETS_UDM_CDS_NEW.TRANSACTION_STATUS T31
ON T0.TRANSACTION_STATUS_SK = T31.ENTITY_SK;
Which takes its data from a table called ORDER_VERSION and refers to it as T0
this table has an index called IDX_ORDER_VERSION
The problem is that oracle ignores my hint, And uses a different index, Now, I have managed to use a hint to make oracle use an index i wanted when i was querying a view that gets data from a table, But this time I am querying a view which gets his data from another view which gets his data from a table.
And also, The second view in the line is on a different Scheme and i am using a synonym, So perhaps that is why i am missing something Cuz i tried many combinations of possible solutions i found on google but nothing seems to be working...
I would say that if i go one step forward and query directly from V_AMV_ORDER_VERSION (Without the synonym) IT works and i can make oracle work with any index i want, so this query works perfect:
select /*+ index(orders.T0 IDX_ORDER_VERSION_5) */ * from V_AMV_ORDER_VERSION orders
where EXCHANGE_SK =32 and PRODUCT_SK = 1000169
Well me and our company's DBA looked at it for a while, it seems like an Oracle bug in the Global Hint manifestation, We have created the view V_AMV_PLG_ORDER_HISTORY_200_MS using a regular join rather than an ANSI join, and now it works properly:
V_AMV_PLG_ORDER_HISTORY_200_MS view SQL Query:
SELECT AMV_PERF_PROFILES_FRONTEND.AMV_PLG_GET_SEGMENT(200, orders.ORDER_GLOBAL_DATE_TIME) AS ORDER_DATE_TIME,
SUM(orders.BASE_VOLUME) AS VOLUME,
SUM(orders.BASE_CURR_LIMIT_PRICE*orders.BASE_VOLUME)/SUM(orders.BASE_VOLUME) AS PRICE,
orders.PRODUCT_SK AS PRODUCT_SK,
orders.EXCHANGE_SK AS EXCHANGE_SK,
orders.DIRECTION_CD AS DIRECTION_CD,
orders.AGG_UNIT_CD AS AGG_UNIT_CD,
orders.TRADER_KEY AS EXECUTING_REPRESENTATIVE_KEY,
orders.ACCOUNT_KEY AS ACCOUNT_KEY,
a.BUSINESS_UNIT_CD AS BUSINESS_UNIT_CD
FROM AMV_PERF_PROFILES_FRONTEND.S_AMV_ORDER_VERSION_NEW orders,
AMV_PERF_PROFILES_FRONTEND.S_AMV_ACCOUNT a
WHERE BASE_VOLUME > 0 AND a.ACCOUNT_KEY = orders.ACCOUNT_KEY
GROUP BY AMV_PERF_PROFILES_FRONTEND.AMV_PLG_GET_SEGMENT(200, orders.ORDER_GLOBAL_DATE_TIME),
orders.PRODUCT_SK,
orders.EXCHANGE_SK,
orders.ACCOUNT_KEY,
a.BUSINESS_UNIT_CD,
orders.AGG_UNIT_CD,
orders.TRADER_KEY,
orders.DIRECTION_CD;

Materialized View involving UNION ALL operator in FROM with ON COMMIT

I have two tables 'survey' & 'survey_processed' and both are basically similar tables. I have a working query which uses UNION ALL operator between two tables & am getting some counts. When I try to translate it in to a Materialized View, I get the error related to ON COMMIT. Check out the MV DDL & Error below.
CREATE MATERIALIZED VIEW vwm_survey_records_count
REFRESH FAST ON COMMIT
AS
SELECT
survey_combined.survey_header_id,
COUNT(*) AS count_total,
COUNT(CASE WHEN survey_combined.processed_flag = 'Y' THEN 1 ELSE NULL END) AS count_a,
COUNT(CASE WHEN survey_combined.approved_flag IS NULL THEN 1 ELSE NULL END) AS count_b,
COUNT(CASE WHEN survey_combined.processed_flag = 'N' AND survey_combined.approved_flag = 'Y' THEN 1 ELSE NULL END) AS count_c,
COUNT(CASE WHEN survey_combined.approved_flag = 'N' THEN 1 ELSE NULL END) AS count_d
FROM
(
SELECT survey_header_id, 'N' AS processed_flag, approved_flag FROM survey
UNION ALL
SELECT survey_header_id, 'Y' AS processed_flag, approved_flag FROM survey_processed) survey_combined
INNER JOIN survey_header ON survey_combined.survey_header_id = survey_header.id
GROUP BY survey_combined.survey_header_id;
Error I get if i run the above command:
'SQL Error: ORA-12054: cannot set the ON COMMIT refresh attribute for the materialized view' .
But, if i use the 'REFRESH COMPLETE ON DEMAND' it works. I know am obviously breaking some restrictions for the ON COMMIT attribute, but can't figure out which. Can someone let me know what am doing wrong on the above query? Also, Is there any better approach for the query as such to make it efficient & work with 'REFRESH FAST ON COMMIT', while creating the MV.
Note: I have the MV Log created for both the tables using rowid on the selected columns.
Let me know if someone has any questions.
Thanks in advance.
Here's the DDL for MV Log as requested by 'jonearles'
CREATE MATERIALIZED VIEW LOG ON survey WITH SEQUENCE,ROWID (id, survey_header_id, approved_flag, processed_flag) INCLUDING NEW VALUES;
CREATE MATERIALIZED VIEW LOG ON survey_processed WITH SEQUENCE,ROWID (id, survey_header_id, approved_flag) INCLUDING NEW VALUES;
CREATE MATERIALIZED VIEW LOG ON survey_header WITH SEQUENCE,ROWID (id) INCLUDING NEW VALUES;
Note: The column 'processed_flag' in the 'survey' table will be dropped later on. Technically, the two tables were recently split based on the value of the 'processed_flag' column. So, the 'survey' table has all the un-processed records (processed_flag = 'N') & 'survey_processed' has the processed records (processed_flag = 'Y'). After the split, the column is irrelevant.
I think you're out of luck here. From Restrictions on Fast Refresh on Materialized Views with UNION ALL:
The defining query must have the UNION ALL operator at the top level.
And replacing the UNION ALL with outer joins doesn't work either. Aggregation and outer joins don't appear to work together. The code below is not equivalent to yours, but it demonstrates that even a much simplified version of your query won't work:
CREATE MATERIALIZED VIEW vwm_survey_records_count
REFRESH COMPLETE ON DEMAND AS
SELECT survey_header.id AS survey_header_id, COUNT(*) AS count_total
FROM survey_header, survey, survey_processed
WHERE survey_header.id = survey.survey_header_id(+)
GROUP BY survey_header.id;
delete from MV_CAPABILITIES_TABLE;
begin
DBMS_MVIEW.EXPLAIN_MVIEW ('VWM_SURVEY_RECORDS_COUNT');
end;
/
select possible, msgno, msgtxt
from MV_CAPABILITIES_TABLE
where capability_name = 'REFRESH_FAST_AFTER_INSERT';
POSSIBLE MSGNO MSGTXT
-------- ----- ------
N 2048 outer join in mv

prevent full table scan

I have following query:
select id,
c1,
c2,
c3
from tbl t1
join
(select id
from tbl t2
where upper(replace(c5, ' ', '')) like upper(?)
) j
on j.id = t1.id
? is some wildcard parameter string like %test%.
c5 column has index on the function used to access it:
create index tbl_c5_idx on tbl(upper(replace(c5, ' ', '')))
When I run just inner query it uses tbl_c5_idx, however when I run the whole query it turns into full table scan which is much slower.
Are there any way to avoid full table scans? Hints or rewrite join condition. I can not rewrite whole query as inner query is constructed dynamically depending on the input conditions.
A very basic example to test your functionality
create table test(id number,value varchar2(200));
insert into test values(1,'gaurav is bad guy');
insert into test values(2,'gaurav is good guy');
SELECT *
FROM test
WHERE UPPER (REPLACE (VALUE, ' ', '')) LIKE UPPER ('%gauravisbad%');
before creating index this is doing a full table scan for obvious reason ,because no index get created.
create index tbl_c5_idx on test(upper(replace(value, ' ', '')));
The reason why i am asking you to avoid inner join on the same table because you're using the table twice once to get your records from your filter condition where your index are used and then join on the basis of id which is preventing of using index ,because you dont have index on id column,this can be done with a simple filter condition.
Please let me know if you're again finding out the same issue of full table scan ,or you're not getting the same result from this query .
if you're running the subquery only, it doesn't use the id column in the filters the way the parent query does, therefore the index can be used. In the parent query you are using the id as well, which prevents the index from being used. Maybe adding an index on (id, upper(replace(c5, ' ', ''))) would solve the problem.
Gaurav Soni is right: you don't need a subquery to achieve your goal.
always check performances rather than the explain plan. Performances might just be worst with your hint than without. Oracle is NOT stupid.
Seems I found solution, or at least a thing that helps.
I used index hint, so access is done with tbl_c5_idx.
That is how final query looks now:
select /*+ index(t1) */ id,
c1,
c2,
c3
from tbl t1
join
(select id
from tbl t2
where upper(replace(c5, ' ', '')) like upper(?)
) j
on j.id = t1.id

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