I use Yii2 a lot but normally with MySQL. This is my first time using it with Oracle. I am finding the performance quite poor though. I've done some googling around and see that although it doesn't appear that common to use Yii2 + Oracle there does seem to be people talking about it being quite slow.
I'm wondering what advice/tips/processes/packages can be employed to improve performance?
I am loading a very small table. It has 8 rows, the entire table has 4 columns. They're are 27 DB calls using 6.4MB of data, that takes about 3 seconds to run. Looking at the logs I see a lot of stuff I don't really understand:
SELECT D.CONSTRAINT_NAME, D.CONSTRAINT_TYPE, C.COLUMN_NAME, C.POSITION, D.R_CONSTRAINT_NAME, E.TABLE_NAME AS TABLE_REF, F.COLUMN_NAME AS COLUMN_REF, C.TABLE_NAME
FROM
ALL_CONS_COLUMNS C
INNER JOIN ALL_CONSTRAINTS D ON D.OWNER = C.OWNER AND D.CONSTRAINT_NAME = C.CONSTRAINT_NAME
LEFT JOIN ALL_CONSTRAINTS E ON E.OWNER = D.R_OWNER AND E.CONSTRAINT_NAME = D.R_CONSTRAINT_NAME
LEFT JOIN ALL_CONS_COLUMNS F ON F.OWNER = E.OWNER AND F.CONSTRAINT_NAME = E.CONSTRAINT_NAME AND F.POSITION = C.POSITION
and
SELECT a.column_name, a.data_type, a.data_precision, a.data_scale, a.data_length,
a.nullable, a.data_default,
( SELECT D.constraint_type
FROM ALL_CONS_COLUMNS C
inner join ALL_constraints D on D.OWNER = C.OWNER and D.constraint_name = C.constraint_name
WHERE C.OWNER = B.OWNER
and C.table_name = B.object_name
and C.column_name = A.column_name
and D.constraint_type = 'P') as Key,
com.comments as column_comment
FROM ALL_TAB_COLUMNS A
inner join ALL_OBJECTS B ON b.owner = a.owner and ltrim(B.OBJECT_NAME) = ltrim(A.TABLE_NAME)
LEFT JOIN all_col_comments com ON (A.owner = com.owner AND A.table_name = com.table_name AND A.column_name = com.column_name)
Then more stuff about triggers.
I also get errors when I try to use relations such as
Model::find()->with('relationName')->all();
I get
'ORA-01795: maximum number of expressions in a list is 1000 error.
These tables collectively have about 17k rows. There's about 11k in one table and about 7k in the other that are linked.
I'm using fk constraints as references within the tables.
Add/Use following settings in your database configurations.
'schemaCacheDuration' => 7200,
'schemaCache' => 'cache',
'enableSchemaCache' => true,
And
change YII_DEBUG from true to false and YII_ENV from dev to prod.
This will reduce unnecessary SQL executions.
Related
I am trying to join three tables using a sub query.
The result of the first left outer join is to be used with another table to get a composite view with all attributes.
I am getting an error where the compile says, Unknown Command for the table in the second join clause.
When I create two independent views and then join then it works fine.
(select
l.ENROLLED_CONTENT,
l.LEARNING_ENROLLMENT_LEARNER,
l.EMPLOYEE_ID,
l.JOB_FAMILY_GROUP,
l.EMPLOYEE_TYPE,
l.JOB_FAMILY,
l.LEARNING_ENROLLMENT,
l.COMPLETION_STATUS,
l.COMPLETION_DATE,
l.EXPIRATION_DATE,
l.CF_LRV_LEARNING_CONTENT_NUMBER,
l.LEARNING_CONTENT_DETAIL,
l.LEARNING_CONTENT_TYPE,
l.LESSON_TYPE,
e.id# "WK_WORKER_ID"
from tgt_workday.learning l
left outer join ods_hrmaster.employee e
on l.EMPLOYEE_ID = e.employee#) t1
left outer join ( select
per_ids_id,
per_id,
id_pureid from
ods_pure.person_ids
) t2 on t1.wk_worker_id = t2.value where t2.type = 'Employee ID';
You can write it in a simple way. There is no need to make sub-queries as:
SELECT L.ENROLLED_CONTENT,
L.LEARNING_ENROLLMENT_LEARNER,
L.EMPLOYEE_ID,
L.JOB_FAMILY_GROUP,
L.EMPLOYEE_TYPE,
L.JOB_FAMILY,
L.LEARNING_ENROLLMENT,
L.COMPLETION_STATUS,
L.COMPLETION_DATE,
L.EXPIRATION_DATE,
L.CF_LRV_LEARNING_CONTENT_NUMBER,
L.LEARNING_CONTENT_DETAIL,
L.LEARNING_CONTENT_TYPE,
L.LESSON_TYPE,
E.ID# "WK_WORKER_ID"
FROM TGT_WORKDAY.LEARNING L
LEFT OUTER JOIN ODS_HRMASTER.EMPLOYEE E
ON L.EMPLOYEE_ID = E.EMPLOYEE#
LEFT OUTER JOIN ODS_PURE.PERSON_IDS T2
ON E.ID# = T2.VALUE
AND T2.TYPE = 'Employee ID';
Once you use the outer joined table's column in WHERE clause, It will result in the same result as inner join(there is another ways to use it in WHERE clause though). So it is better to avoid using outer joined table's column in the WHERE clause.
Try as
SELECT *
FROM ( (SELECT l.ENROLLED_CONTENT,
l.LEARNING_ENROLLMENT_LEARNER,
l.EMPLOYEE_ID,
l.JOB_FAMILY_GROUP,
l.EMPLOYEE_TYPE,
l.JOB_FAMILY,
l.LEARNING_ENROLLMENT,
l.COMPLETION_STATUS,
l.COMPLETION_DATE,
l.EXPIRATION_DATE,
l.CF_LRV_LEARNING_CONTENT_NUMBER,
l.LEARNING_CONTENT_DETAIL,
l.LEARNING_CONTENT_TYPE,
l.LESSON_TYPE,
e.id# "WK_WORKER_ID"
FROM tgt_workday.learning l
LEFT OUTER JOIN ods_hrmaster.employee e
ON l.EMPLOYEE_ID = e.employee) t1
LEFT OUTER JOIN
(SELECT per_ids_id, per_id, id_pureid FROM ods_pure.person_ids) t2
ON t1.wk_worker_id = t2.VAL AND t2.TYPE = 'Employee ID')
I am new to PostgreSQL and was wondering if there is a table which matches Oracle's user_cons_columns table which provides a column position column similar to user_cons_columns.position. Essentially, I am trying to convert the following oracle code to PostgreSQL. It attains the PK columns in order of PK definition:
Oracle Code (Original):
select a.table_name tab_name,
a.colum_name col_name,
a.position col_order
from user_cons_columns a,
user_constraints b
where a.table_name = b.table_name
and a.constraint_name = b.constraint_name
and b.constraint_type = 'P'
and a.table_name = 'some_table_name';
PostgreSQL Code (Oracle Equiv):
/* Below is my attempt at the PostgreSQL conversion */
select isc.table_name tab_name,
isc.column_name col_name,
isc.ordinal_position col_order
from pg_attribute as pga
inner join pg_class as pgc on pga.attrelid = pgc.oid
inner join pg_namespace as pgn on pgn.oid = pgc.relnamespace
inner join information_schema.columns as isc on isc.column_name = pga.attname
and isc.table_name = pgc.relname
where isc.table_name = 'sometablename';
In my PostgreSQL conversion attempt I am missing the relationship between the constraint and its position but use the column position. Which is not the same. Is there a way to do the former? Thanks in advance!
The column numbers of a constraint and their order are stored in pg_constraint.conkey; for foreign keys, the corresponding numbers of the target columns are in pg_constraint.confkey.
The description of table columns is in pg_attribute; the column number is stored in attnum.
Below is the solution that I derived thanks to the answer from #Laurenz Albe.
select isc.table_name tab_name,
isc.col_name col_name,
pgco.conkey[1] col_order
from pg_attribute as pga
inner join pg_class as pgc on pga.attrelid = pgc.oid
inner join pg_namespace as pgn on pgn.oid = pgc.relnamespace
inner join information_schema.columns as isc on isc.column = pga.attname
and isc.table_name = pgc.relname
inner join pg_constraint as pgco on pgco.conkey[1] = pga.attnum
and pgco.connamespace = pgc.relnamespace
and pgco.conrelid = pga.attrelid
where isc.table_name = 'sometablename'
and pgco.contype ='p';
Hope this is useful to someone else.
select col_1,
col_2
from tbl_a A,
tbl_b B,
( select col_1,col_2 from tbl_c where clo_c_1 <> '1' ) C
where A.col_1 = B.col_1
and A.col_2 = B.col_2
and (A.col_2 = B.col_2
or C.col_2 = A.col_2);
My environment is Oracle,when I run this SQL,if the sub SQL C hasn't got a result,then the entire SQL returns NULL.Whereas if C has a result(not null) which fits other condions,there could be a result.Would somebody explain why sub SQL at the from area need to be not NULL?Thanks very much.
You need to bring yourself into the 90s and start using standard joins:
select col_1,
col_2
from tbl_a A
inner join
tbl_b B
on A.col_1 = B.col_1
and A.col_2 = B.col_2
left join
( select col_1,col_2 from tbl_c where clo_c_1 <> '1' ) C
on
C.col_2 = A.col_2
As a guess. I'm not entirely sure what your join conditions should be but that's my first attempt.
This is expected behaviour. When you join two result sets, you only want to get results where the join criteria is satisfied. If the criteria are not satisfied, you should get no results.
If I run the query "get me all the employees older than 65, and get their departments", if there are no employees older than 65, you would not expect to get any results, even if there are some departments in the database.
SELECT emp.name, dept.dept_name
FROM emp
JOIN dept
ON (emp.dept_no = dept.dept_no)
WHERE emp.age > 65;
As the others said, if you actually want to get rows regardless of whether the subquery has any results, you need to use an outer join.
SQL Query (Execution plan cost = 0.0127553)
SELECT
SUM(DATEDIFF(second, DTActivate, DTDeActivate)) AS Seconds,
AA.ID AS AAID,
AA.WorkStation
FROM
DbLogItems I
INNER JOIN DbApplicationArguments AA ON
AA.Id = I.ApplicationArgument_ID
GROUP BY
AA.ID,
AA.WorkStation
C#
var q = from items in db.LogItem
join aa in db.ApplicationArguments on
items.ApplicationArgument.ID equals aa.ID
into aaGroup
from aaJoin in aaGroup.DefaultIfEmpty()
group items by new
{
aaJoin.ID,
aaJoin.WorkStation
} into grouping
select new
{
Seconds = grouping.Sum(x => SqlFunctions.DateDiff("second", x.DTActivate, x.DTDeActivate)),
grouping.Key.ID,
grouping.Key.WorkStation
};
Result SQL very big (Execution plan cost = 0.0199849)
SELECT
1 AS [C1],
[GroupBy1].[A1] AS [C2],
[GroupBy1].[K1] AS [ID],
[GroupBy1].[K2] AS [WorkStation]
FROM
(
SELECT
[Join1].[K1] AS [K1],
[Join1].[K2] AS [K2],
SUM([Join1].[A1]) AS [A1]
FROM
(
SELECT
[Extent2].[ID] AS [K1],
[Extent2].[WorkStation] AS [K2],
DATEDIFF(second, [Extent1].[DTActivate], [Extent1].[DTDeActivate]) AS [A1]
FROM
[dbo].[DbLogItems] AS [Extent1]
LEFT OUTER JOIN [dbo].[DbApplicationArguments] AS [Extent2]
ON [Extent1].[ApplicationArgument_ID] = [Extent2].[ID]
) AS [Join1]
GROUP BY
[K1],
[K2]
) AS [GroupBy1]
help please write correct linq code.
My SQL Execution plan cost = 0.0127553.
Linq SQL Execution plan cost = 0.0199849.
DIFF = 0,0072296 on 21+10 records
LINQ to SQL queries are what they are. Sometimes you can't emit better SQL. However, you can write plain old T-SQL and call it in a number ways: a table-valued UDF perhaps that your customized DataContext exposes as an IQueryable.
I've inherited a schema so don't have complete knowledge/confidence in what is there.
I have a project table with a projectId. There are a whole bunch of other tables that reference this table by project id. What I want to do is run a query to establish:
Which tables have foreign key references to the project table on
the project id
Which tables have a column called project id (in
case foreign keys are not set up).
If it was SQL Server I know how to query the metadata but how do I do this in Oracle?
1)
select table_name
from all_constraints
where r_constraint_name = [your pk/uk constraint on PROJECTS(id)]
2)
select table_name
from all_tab_columns
where column_name = 'PROJECT_ID'
You may want to add an extra predicate containing the OWNER column.
Regards,
Rob.
Ok. Here a request that give you the referenced table and column :
SELECT
c_list.CONSTRAINT_NAME as NAME,
substr(c_src.COLUMN_NAME, 1, 20) as SRC_COLUMN,
c_dest.TABLE_NAME as DEST_TABLE,
substr(c_dest.COLUMN_NAME, 1, 20) as DEST_COLUMN
FROM ALL_CONSTRAINTS c_list, ALL_CONS_COLUMNS c_src, ALL_CONS_COLUMNS c_dest
WHERE c_list.CONSTRAINT_NAME = c_src.CONSTRAINT_NAME
AND c_list.OWNER = c_src.OWNER
AND c_list.R_CONSTRAINT_NAME = c_dest.CONSTRAINT_NAME
AND c_list.OWNER = c_dest.OWNER
AND c_list.CONSTRAINT_TYPE = 'R'
AND c_src.OWNER = '<your-schema-here>'
AND c_src.TABLE_NAME = '<your-table-here>'
GROUP BY c_list.CONSTRAINT_NAME, c_src.TABLE_NAME,
c_src.COLUMN_NAME, c_dest.TABLE_NAME, c_dest.COLUMN_NAME;
Which give you something like this:
NAME |SRC_COLUMN |DEST_TABLE | DEST_COLUMN
----------------------|----------------|----------------------|-----------
CFK_RUB_FOR |FOR_URN |T03_FORMAT |FOR_URN
CFK_RUB_RUB |RUB_RUB_URN |T01_RUBRIQUE |RUB_URN
CFK_RUB_SUP |SUP_URN |T01_SUPPORT |SUP_URN
CFK_RUB_PRD |PRD_URN |T05_PRODUIT |PRD_URN
You can forget the substr() function if the result is usable without. This is not my case.
1): SELECT * FROM USER_CONSTRAINTS WHERE CONSTRAINT_NAME='R' and R_CONSTRAINT_NAME='xxx'
where xxx is the name of the primary key constraint on the project table
2): SELECT * FROM USER_TAB_COLUMNS WHERE COLUMN_NAME='PROJECT_ID'
The r_constraint_name answers here didn't seem to work for me, not sure why as I'm new to Oracle myself, but this worked:
SELECT * FROM ALL_CONSTRAINTS WHERE CONSTRAINT_NAME = '<constraint>';
My problem was slightly different. I have a table and I wanted to programatically know which other tables/columns it references.
I started with Stan's response above but this didn't give me exactly what I needed, so I came up with this, which I post here in case anyone else has my problem:
WITH src as
(SELECT ac.table_name, ac.constraint_name, accs.column_name, accs.position, ac.r_constraint_name
FROM ALL_CONSTRAINTS ac, all_cons_columns accs
WHERE ac.owner = '<owner>'
AND ac.constraint_type = 'R'
AND ac.table_name = '<src_table>'
AND accs.owner = ac.owner
AND accs.table_name = ac.table_name
AND accs.constraint_name = ac.constraint_name
ORDER BY ac.table_name, ac.constraint_name, accs.position),
dst as
(SELECT ac.table_name, ac.constraint_name, accs.column_name, accs.position
FROM ALL_CONSTRAINTS ac, all_cons_columns accs
WHERE ac.owner = '<owner>'
AND accs.owner = ac.owner
AND accs.table_name = ac.table_name
AND accs.constraint_name = ac.constraint_name
ORDER BY ac.table_name, ac.constraint_name, accs.position)
SELECT src.table_name as src_table,
dst.table_name as dst_table,
src.constraint_name as src_constraint,
src.column_name as src_column,
dst.column_name as dst_column,
src.position as position
FROM src,dst
WHERE src.r_constraint_name = dst.constraint_name
AND src.position = dst.position
Use this query.
select b.TABLE_NAME,b.CONSTRAINT_NAME ,a.COLUMN_NAME
from all_constraints b, all_cons_columns a
where r_constraint_name = 'Constraint_Name' and a.CONSTRAINT_NAME=b.CONSTRAINT_NAME;