All -
I'm looking at a large volume of sql query history data. Ultimately I need to create a distinct list of tables used by each from a list of their executed queries. Let's say my simplified table for this example is:
create table zwork_example (
username varchar2(50),
sql_text clob);
insert into zwork_example (username, sql_text)
values ('user1', 'schema1.table1, schema1.table2, schema2.table1, schema1.table1');
insert into zwork_example (username, sql_text)
Values ('user2', 'schema1.table3, schema1.table2, schema2.table1, schema1.table6');
Does anyone have any ideas on how I can search for schema1* and return N number of table names that belong to schema1? In this example I have a particular schema I'm interested in, so I can explicitly state that schema1 is the only schema I'm interested in returning the table names from.
The output I would look for given this example is:
User Schema Tables
-------- -------- --------
User1 schema1 table1, table2
User2 schema1 table3, table2, table6
CLOB, large data set ... doesn't sound promising. Read: it'll probably take some time to get the result. For such a small data set, see if this helps.
SQL> with
2 search_for (schema) as
3 (select 'schema1' from dual),
4 temp as
5 (select distinct
6 username,
7 trim(regexp_substr(dbms_lob.substr(sql_text, 32767), '[^,]+', 1, column_value)) col
8 from zwork_example cross join
9 table(cast(multiset(select level from dual
10 connect by level <= regexp_count(sql_text, ',') + 1
11 ) as sys.odcinumberlist))
12 )
13 select
14 t.username,
15 s.schema,
16 listagg(trim(replace(t.col, s.schema ||'.', null)), ', ') within group (order by null) tables
17 from temp t join search_for s on instr(t.col, s.schema) > 0
18 group by t.username, s.schema;
USERNAME SCHEMA TABLES
---------- ------- --------------------------------------------------
user1 schema1 table1, table2
user2 schema1 table2, table3, table6
SQL>
What does it do?
search_for CTE contains a schema you're searching for (schema1, right?)
temp CTE splits the sql_text into rows
moreover, in order to get distinct list of tables, I applied dbms_lob.substr to the column, hoping that you don't actually have strings longer than that (32767, that is)
final query just aggregates tables it found - rows where schemas match
For a large dataset you can use:
WITH search_string ( schema_name ) AS (
SELECT 'schema1' FROM DUAL
),
matches ( username, sql_text, schema_name, end_pos, matches ) AS (
SELECT username,
sql_text,
schema_name,
CASE
WHEN sql_text LIKE schema_name || '%'
THEN INSTR( sql_text, ',' )
WHEN sql_text NOT LIKE ', ' || schema_name || '.'
THEN 0
ELSE INSTR(
sql_text,
', ' || schema_name || '.',
INSTR( sql_text, ', ' || schema_name || '.' ) + 3
)
END,
CASE
WHEN sql_text LIKE schema_name || '%'
THEN EMPTY_CLOB() || SUBSTR(
sql_text,
LENGTH(schema_name || '.') + 1,
INSTR( sql_text, ',' ) - LENGTH(schema_name || '.') - 1
)
WHEN INSTR( sql_text, ', ' || schema_name || '.' ) = 0
THEN NULL
WHEN INSTR( sql_text, ',', INSTR( sql_text, ', ' || schema_name || '.' ) + 3 ) = 0
THEN EMPTY_CLOB() || SUBSTR(
sql_text,
INSTR( sql_text, ', ' || schema_name || '.' )
+ LENGTH(', ' || schema_name || '.')
)
ELSE EMPTY_CLOB() || SUBSTR(
sql_text,
INSTR( sql_text, ', ' || schema_name || '.' )
+ LENGTH(', ' || schema_name || '.'),
INSTR( sql_text, ',', INSTR( sql_text, ', ' || schema_name || '.' ) + 3 )
- INSTR( sql_text, ', ' || schema_name || '.' )
- LENGTH(', ' || schema_name || '.')
)
END
FROM zwork_example
CROSS JOIN search_string
UNION ALL
SELECT username,
sql_text,
schema_name,
INSTR(
sql_text,
', ' || schema_name || '.',
end_pos + 3
),
matches
|| ', '
|| CASE
WHEN INSTR( sql_text, ',', end_pos + 1 ) = 0
THEN SUBSTR(
sql_text,
end_pos + LENGTH(', ' || schema_name || '.')
)
ELSE SUBSTR(
sql_text,
end_pos + LENGTH(', ' || schema_name || '.'),
INSTR( sql_text, ',', end_pos + 1 )
- end_pos - LENGTH(', ' || schema_name || '.')
)
END
FROM matches
WHERE end_pos > 0
)
SELECT username,
matches
FROM matches
WHERE end_pos = 0;
Which, for the sample data:
create table zwork_example (
username varchar2(50),
sql_text clob
);
DECLARE
v_text CLOB;
BEGIN
insert into zwork_example (username, sql_text)
values ('user1', 'schema1.table1, schema1.table2, schema2.table1, schema1.table1');
insert into zwork_example (username, sql_text)
Values ('user2', 'schema1.table3, schema1.table2, schema2.table1, schema1.table6');
insert into zwork_example (username, sql_text)
Values ('user3', 'schema2.table3, schema3.table2, schema4.table1, schema2.table6');
insert into zwork_example (username, sql_text)
Values ('user4', 'schema2.table3, schema3.table2, schema4.table1, schema1.table6');
v_text := 'schema1.table1';
FOR i IN 2 .. 250 LOOP
v_text := v_text || ', schema1.table' || i;
END LOOP;
insert into zwork_example (username, sql_text) values ( 'user5', v_text );
END;
/
Outputs:
USERNAME
MATCHES
user3
user4
table6
user1
table1, table2, table1
user2
table3, table2, table6
user5
table1, table2, table3, table4, table5, table6, table7, table8, table9, table10, table11, table12, table13, table14, table15, table16, table17, table18, table19, table20, table21, table22, table23, table24, table25, table26, table27, table28, table29, table30, table31, table32, table33, table34, table35, table36, table37, table38, table39, table40, table41, table42, table43, table44, table45, table46, table47, table48, table49, table50, table51, table52, table53, table54, table55, table56, table57, table58, table59, table60, table61, table62, table63, table64, table65, table66, table67, table68, table69, table70, table71, table72, table73, table74, table75, table76, table77, table78, table79, table80, table81, table82, table83, table84, table85, table86, table87, table88, table89, table90, table91, table92, table93, table94, table95, table96, table97, table98, table99, table100, table101, table102, table103, table104, table105, table106, table107, table108, table109, table110, table111, table112, table113, table114, table115, table116, table117, table118, table119, table120, table121, table122, table123, table124, table125, table126, table127, table128, table129, table130, table131, table132, table133, table134, table135, table136, table137, table138, table139, table140, table141, table142, table143, table144, table145, table146, table147, table148, table149, table150, table151, table152, table153, table154, table155, table156, table157, table158, table159, table160, table161, table162, table163, table164, table165, table166, table167, table168, table169, table170, table171, table172, table173, table174, table175, table176, table177, table178, table179, table180, table181, table182, table183, table184, table185, table186, table187, table188, table189, table190, table191, table192, table193, table194, table195, table196, table197, table198, table199, table200, table201, table202, table203, table204, table205, table206, table207, table208, table209, table210, table211, table212, table213, table214, table215, table216, table217, table218, table219, table220, table221, table222, table223, table224, table225, table226, table227, table228, table229, table230, table231, table232, table233, table234, table235, table236, table237, table238, table239, table240, table241, table242, table243, table244, table245, table246, table247, table248, table249, table250
db<>fiddle here
I have been trying hard to optimize below query using indexes in place of where clause. can any one help on the same. Data volume is very high so I want to optimize it using indexing or anyother way?
Query goes like this:
SELECT *
FROM
(SELECT
a.*,
rownum as row_num
FROM
(SELECT DISTINCT
lot.lot_no AS lotNo, lot.sel as sel,
lot.C_ARRIVAL_NOTICE_NO AS arrNoticeNo,
lot.C_SHIPMENT_DIRECTION AS shipmentDirection,
lot.C_SENDERS_REFERENCE_NUM AS externalReference,
lot.booking_seq AS bookingNo,lot.shipper AS shipperCode,
nvl(lot.shipper_name ,lot.shipper_addr1) AS shipperName,
NVL2 (lot.commdesc, lot.commdesc || ' ', '') || NVL2 (lot.comdesc1,lot. comdesc1 || ' ', '') || NVL2 (lot.comdesc2, lot.comdesc2 || ' ', '') || NVL2 (lot.comdesc3, lot.comdesc3 || ' ', '') || NVL2 (lot.comdesc4, lot.comdesc4 || ' ', '') || NVL2 (lot.comdesc5, lot.comdesc5 || ' ', '') || NVL2 (lot.comdesc6,lot. comdesc6 || ' ', '') || NVL2 (lot.comdesc7,lot. comdesc7 || ' ', '') || NVL2 (lot.comdesc8, lot.comdesc8 || ' ', '') || NVL2 (lot.comdesc9, lot.comdesc9, '') AS description,
lot.lot_qty AS pieces, lot.lot_wght AS weight,
lot.lot_cube AS cube,
to_char(lot.input_date, 'dd-Mon-YYYY') AS lotDate,
lot.e_m AS e_m, lot.warehouse AS warehouse,
to_char(lot.in_date , 'dd-Mon-YYYY') AS inDate,
lot.in_time AS inTime, lot.hold AS hold,
to_char(lot.sail_date, 'dd-Mon-YYYY') AS sailDate,
to_char(lot.sail_date, 'dd-Mon-YYYY') AS etdDate,
lot.container AS container,
lot.oml_bl_no AS billOfLadingNumber,
lot.reference AS fileNumber,
lot.inland_carrier AS trucker,
lot.pro_number AS proNumber,
lot.comments AS exceptions, lot.vessel AS vessel,
lot.cstatus AS status, lot.voyage AS voyage,
(SELECT count(*) FROM tra_shipment_status
WHERE c_reference = lot.lot_no AND i_status_code = '857940') as transmitcount,
(SELECT c_finalcfs_code FROM imp_bl_top
WHERE inv_no = lot.C_Arrival_Notice_No) as cfsCode,
'STI_COUNTRY_US' AS schemaName
FROM
itemdata lot
WHERE
lot.in_date BETWEEN TO_DATE('27-FEB-2017 00:00', 'DD-MON-YYYY HH24:MI')
AND TO_DATE('29-MAR-2017 23:59', 'DD-MON-YYYY HH24:MI')
AND lot.sel IS NOT NULL
AND (lot.C_ARRIVAL_NOTICE_NO IS NOT NULL OR
lot.C_SHIPMENT_DIRECTION ='IO')
AND lot.I_STATUS > 0 AND Lot.Cstatus = 'D'
ORDER BY
lot.lot_no desc, lot.in_date desc) a
WHERE
rownum <= 60)
WHERE
row_num >= 1