Mariadb Parititioning - database

There is table named history in Zabbix database, I have created partitions on this table.
And the partition type is range and column type is UNIX_TYPESTAMP.
After the date is changed zabbix service does not insert data to the related partition.
What is the problem?
And how do I display all partitions?
Could you please help how do I write data to the related partitions?
Sample of Partition creation statement;
.
.
.
ALTER TABLE zabbix.history_test PARTITION BY RANGE(clock)(PARTITION
p28082021 VALUES LESS THAN(UNIX_TIMESTAMP("2021-08-28 00:00:00"
))ENGINE=InnoDB);
Server version: 10.1.31-MariaDB MariaDB Server
EXPLAIN PARTITIONS SELECT * FROM zabbix.history;
+------+-------------+---------+------------+------+---------------+------
| id | select_type | table | partitions | type | possible_keys | key |
key_len | ref | rows | Extra |
| 1 | SIMPLE | history | p28082021 | ALL | NULL | NULL
| NULL | NULL | 18956757 | |
SELECT DISTINCT PARTITION_EXPRESSION FROM
INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_NAME='history' AND
TABLE_SCHEMA='zabbix';
+----------------------+
| PARTITION_EXPRESSION |
+----------------------+
| clock |
+----------------------+
MariaDB [(none)]> SELECT PARTITION_ORDINAL_POSITION, TABLE_ROWS, PARTITION_METHOD
FROM information_schema.PARTITIONS
WHERE TABLE_SCHEMA = 'zabbix' AND TABLE_NAME = 'history';
+----------------------------+------------+------------------+
| PARTITION_ORDINAL_POSITION | TABLE_ROWS | PARTITION_METHOD |
+----------------------------+------------+------------------+
| 1 | 18851132 | RANGE |
+----------------------------+------------+------------------+
SELECT FROM_UNIXTIME(MAX(clock)) FROM zabbix.history;
+---------------------------+
| FROM_UNIXTIME(MAX(clock)) |
+---------------------------+
| 2018-04-07 23:06:06 |
+---------------------------+
SELECT FROM_UNIXTIME(MIN(clock)) FROM zabbix.history;
+---------------------------+
| FROM_UNIXTIME(MIN(clock)) |
+---------------------------+
| 2018-04-06 01:06:23 |
+---------------------------+

This document help me to create partition on clock column.
There are stored procedures, that create partitions,you can check it.
https://www.zabbix.org/wiki/Docs/howto/mysql_partition

Related

How to mark selected columns of a table for display

I use PostgreSQL 10.1 and:
CREATE TABLE human
(
id ... NOT NULL,
gender ...,
height ...,
weight ...,
eye ...,
hair ...,
...
);
I have an input form through which I insert the data. I wish an elegant and proper way by which I can SELECT which columns required to be DISPLAYED in that form, something like weight ... DISPLAYED, or eye ... NOT DISPLAYED, .
One way is to correspond NULL with DISPLAYED (when NOT NULL then display it, or when NULL then do not display it) and use information_schema which (corresponding) makes me no so happy:
Another way is to:
CREATE TABLE human_column
(
id ... NOT NULL,
characteristic character varying(...),
is_displayed boolean
);
where characteristic data are the names of the columns of human table.
Is there a better way to add a direct foreign attribute to the columns of a table? (In 51.7. pg_attribute there is a column named attoptions. Would it be used?)
specifying "options" for columns to define if they will be "displayed" or not seems a little overhead. Imagine you keep such list in human_column. To modify it you would need to update it with new is_displayed values. Then you would need to build column list to be selected in query.
When you create a view, you do the same (specify a list of columns to be displayed) and then you can just query the view, without need to dynamically build the query. Also you can always check the current list of included columns from catalog or information_schema.
The only "not cosy" feature of a view - you can't change columns in it, thus you have to drop and create it again.
drop/create view on demand looks cheaper to me then dynamically building query with list of columns on each select still.
demo:
db=# create view v as select oid,datname from pg_database;
CREATE VIEW
db=# select * from v;
oid | datname
-------+-----------
13505 | postgres
16384 | t
1 | template1
13504 | template0
16419 | o
(5 rows)
checking list of columns:
db=# select column_name,ordinal_position,column_default,is_nullable,data_type,character_maximum_length from information_schema.columns where table_name = 'v';
column_name | ordinal_position | column_default | is_nullable | data_type | character_maximum_length
-------------+------------------+----------------+-------------+-----------+--------------------------
oid | 1 | | YES | oid |
datname | 2 | | YES | name |
(2 rows)
same for original table:
db=# select column_name,ordinal_position,column_default,is_nullable,data_type,character_maximum_length from information_schema.columns where table_name = 'pg_database';
column_name | ordinal_position | column_default | is_nullable | data_type | character_maximum_length
---------------+------------------+----------------+-------------+-----------+--------------------------
datname | 1 | | NO | name |
datdba | 2 | | NO | oid |
encoding | 3 | | NO | integer |
datcollate | 4 | | NO | name |
datctype | 5 | | NO | name |
datistemplate | 6 | | NO | boolean |
datallowconn | 7 | | NO | boolean |
datconnlimit | 8 | | NO | integer |
datlastsysoid | 9 | | NO | oid |
datfrozenxid | 10 | | NO | xid |
datminmxid | 11 | | NO | xid |
dattablespace | 12 | | NO | oid |
datacl | 13 | | YES | ARRAY |
(13 rows)

SQL Server - Is it possible to define a table column as a table?

I know that this is possible in Oracle and I wonder if SQL Server also supports it (searched for answer without success).
It would greatly simplify my life in the current project if I could define a column of a table to be a table itself, something like:
Table A:
Column_1 Column_2
+----------+----------------------------------------+
| 1 | Columns_2_1 Column_2_2 |
| | +-------------+------------------+ |
| | | 'A' | 12345 | |
| | +-------------+------------------+ |
| | | 'B' | 777777 | |
| | +-------------+------------------+ |
| | | 'C' | 888888 | |
| | +-------------+------------------+ |
+----------+----------------------------------------+
| 2 | Columns_2_1 Column_2_2 |
| | +-------------+------------------+ |
| | | 'X' | 555555 | |
| | +-------------+------------------+ |
| | | 'Y' | 666666 | |
| | +-------------+------------------+ |
| | | 'Z' | 000001 | |
| | +-------------+------------------+ |
+----------+----------------------------------------+
Thanks in advance.
There is one option where you can store data as XML
Declare #YourTable table (ID int,XMLData xml)
Insert Into #YourTable values
(1,'<root><ID>1</ID><Active>1</Active><First_Name>John</First_Name><Last_Name>Smith</Last_Name><EMail>john.smith#email.com</EMail></root>')
,(2,'<root><ID>2</ID><Active>0</Active><First_Name>Jane</First_Name><Last_Name>Doe</Last_Name><EMail>jane.doe#email.com</EMail></root>')
Select ID
,Last_Name = XMLData.value('(root/Last_Name)[1]' ,'nvarchar(50)')
,First_Name = XMLData.value('(root/First_Name)[1]' ,'nvarchar(50)')
From #YourTable
Returns
ID Last_Name First_Name
1 Smith John
2 Doe Jane
Actually, for a normalized database we do not require such functionality.
Because if we need to insert a table within a column than we can create a child table and reference it as a foreign key in the parent table.
In spite, if you still insist to such functionality than you can use SQL Server 2016 to support JSON data where you can store any associative list in JSON format.
Like:
DECLARE #json NVARCHAR(4000)
SET #json =
N'{
"info":{
"type":1,
"address":{
"town":"Bristol",
"county":"Avon",
"country":"England"
},
"tags":["Sport", "Water polo"]
},
"type":"Basic"
}'
SELECT
JSON_VALUE(#json, '$.type') as type,
JSON_VALUE(#json, '$.info.address.town') as town,
JSON_QUERY(#json, '$.info.tags') as tags
SELECT value
FROM OPENJSON(#json, '$.info.tags')
In older versions, this can be achieved through xml as shown in previous answer.
Your can also make use of "sql_variant" datatype to map your table.
Previously, I was also in search of such features as available in Oracle. But after reading various articles and blogs from experts, I was convinced, such features will make the things more complex beside helping.
Only storing the data in required format is not important, It is worthy when it is also efficiently available (readable).
Hope this will help you to take your decision.

T-SQL Merging data

I've imported data from an XML file by using SSIS to SQL Server.
The result what I got in the database is similar to this:
+-------+---------+---------+-------+
| ID | Name | Brand | Price |
+-------+---------+---------+-------+
| 2 | NULL | NULL | 100 |
| NULL | SLX | NULL | NULL |
| NULL | NULL | Blah | NULL |
| NULL | NULL | NULL | 100 |
+-------+---------+---------+-------+
My desired result would be:
+-------+---------+---------+-------+
| ID | Name | Brand | Price |
+-------+---------+---------+-------+
| 2 | SLX | Blah | 100 |
+-------+---------+---------+-------+
Is there a pretty solution to solve this in T-SQL?
I've already tried it with a SELECT MAX(ID) and then a GROUP BY ID, but I'm still stuck with the NULL values. Also I've tried it with MERGE, but also a failure.
Could someone give me a direction where to search further?
You can select MAX on all columns....
SELECT MAX(ID), MAX(NAME), MAX(BRAND), MAX(PRICE)
FROM [TABLE]
Click here for a fiddley fidd fiddle...

Netezza SQL to find Client IP

Is there any way to return the client IP address in Netezza? In Oracle we run below query .
SELECT SYS_CONTEXT('USERENV','IP_ADDRESS') FROM dual;
Thanks
This query can get you all the information you need about the current_session.
select client_ip
from _v_session_detail
where session_id= CURRENT_SID
You can use "show session" to provide that information if you aren't trying to access it as a column in a table.
SYSTEM.ADMIN(ADMIN)=> SYSTEM.ADMIN(ADMIN)=> show session;
SESSION_ID | PID | USERNAME | DBNAME | SCHEMA | TYPE | CONNECT_TIME | SESSION_STATE_NAME | SQLTEXT | PRIORITY_NAME | CLIENT_PID | CLIENT_IP | CLIENT_OS_USERNAME
------------+-------+----------+--------+--------+------+---------------------+--------------------+--------------+---------------+------------+-----------+--------------------
16228 | 10272 | ADMIN | SYSTEM | ADMIN | sql | 2014-12-10 10:56:48 | active | show session | normal | 10271 | 127.0.0.1 |
(1 row)
You can also query against the _v_session, which will report on sessions you have visibility/authorization to see, but doesn't necessarily tell you which one is yours. For a non-administrative user this is usually only your sessions, so it should be easy to tell.
SYSTEM.ADMIN(ADMIN)=> select * from _v_session;
ID | PID | USERNAME | DBNAME | TYPE | CONNTIME | STATUS | COMMAND | PRIORITY | CID | IPADDR | CLIENT_OS_USERNAME
-------+-------+----------+--------+------+---------------------+--------+--------------------------+----------+-------+-----------+--------------------
16228 | 10272 | ADMIN | SYSTEM | sql | 2014-12-10 10:56:48 | active | select * from _v_session | 3 | 10271 | 127.0.0.1 |
(1 row)
If you want information only about the particular session in which you are calling the query, then this will do the trick.
SYSTEM.ADMIN(ADMIN)=> select * from _v_session where id = current_sid;
ID | PID | USERNAME | DBNAME | TYPE | CONNTIME | STATUS | COMMAND | PRIORITY | CID | IPADDR | CLIENT_OS_USERNAME
-------+-------+----------+--------+------+---------------------+--------+-------------------------------------------------+----------+-------+-----------+--------------------
16837 | 22310 | ADMIN | SYSTEM | sql | 2014-12-10 19:06:21 | active | select * from _v_session where id = current_sid | 3 | 22309 | 127.0.0.1 |
(1 row)
I should note that what you're looking for here is already being tracked by the query history database, which is most likely already configured on your system.

CakePHP access indirectly related model - beginner's question

I am writing a CakePHP application to log the work I do for various clients, but after trying for days I seem unable to get it to do what I want. I have read most of the book CakePHP's website.
and googled for all I'm worth, so I presume I am missing something obvious!
Every 'log item' belongs to a 'sub-project, which in turn belongs to a 'project', which in turn belongs to a 'sub-client' which finally belongs to a client. These are the 5 MySQL tables I am using:
mysql> DESCRIBE log_items;
+-----------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| date | date | NO | | NULL | |
| time | time | NO | | NULL | |
| time_spent | int(11) | NO | | NULL | |
| sub_projects_id | int(11) | NO | MUL | NULL | |
| title | varchar(100) | NO | | NULL | |
| description | text | YES | | NULL | |
| created | datetime | YES | | NULL | |
| modified | datetime | YES | | NULL | |
+-----------------+--------------+------+-----+---------+----------------+
mysql> DESCRIBE sub_projects;
+-------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(100) | NO | | NULL | |
| projects_id | int(11) | NO | MUL | NULL | |
| created | datetime | YES | | NULL | |
| modified | datetime | YES | | NULL | |
+-------------+--------------+------+-----+---------+----------------+
mysql> DESCRIBE projects;
+----------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(100) | NO | | NULL | |
| sub_clients_id | int(11) | NO | MUL | NULL | |
| created | datetime | YES | | NULL | |
| modified | datetime | YES | | NULL | |
+----------------+--------------+------+-----+---------+----------------+
mysql> DESCRIBE sub_clients;
+------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(100) | NO | | NULL | |
| clients_id | int(11) | NO | MUL | NULL | |
| created | datetime | YES | | NULL | |
| modified | datetime | YES | | NULL | |
+------------+--------------+------+-----+---------+----------------+
mysql> DESCRIBE clients;
+----------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(100) | NO | | NULL | |
| created | datetime | YES | | NULL | |
| modified | datetime | YES | | NULL | |
+----------+--------------+------+-----+---------+----------------+
I have set up the following associations in CakePHP:
LogItem belongsTo SubProjects
SubProject belongsTo Projects
Project belongsTo SubClients
SubClient belongsTo Clients
Client hasMany SubClients
SubClient hasMany Projects
Project hasMany SubProjects
SubProject hasMany LogItems
Using 'cake bake' I have created the models, controllers (index, view add, edit and delete) and views, and things seem to function - as in I am able to perform simple CRUD operations successfully.
The Question
When editing a 'log item' at www.mydomain/log_items/edit I am presented with the view you would all suspect; namely the columns of the log_items table with the appropriate textfields/select boxes etc. I would also like to incorporate select boxes to choose the client, sub-client, project and sub-project in the 'log_items' edit view.
Ideally the 'sub-client' select box should populate itself depending upon the 'client' chosen, the 'project' select box should also populate itself depending on the 'sub-client' selected etc, etc.
I guess the way to go about populating the select boxes with relevant options is Ajax, but I am unsure of how to go about actually accessing a model from the child view of a indirectly related model, for example how to create a 'sub-client' select box in the 'log_items' edit view.
I have have found this example:
http://forum.phpsitesolutions.com/php-frameworks/cakephp/ajax-cakephp-dynamically-populate-html-select-dropdown-box-t29.html
where someone achieves something similar for US states, counties and cities. However, I noticed in the database schema - which is downloadable from the site above link - that the database tables don't have any foreign keys, so now I'm wondering if I'm going about things in the correct manner.
Any pointers and advice would be very much appreciated.
Kind regards,
Chris
Your foreign key names should be singular. So projects_id should be project_id and sub_projects_id should be sub_project_id and so forth. If you are using cake bake or scaffolding, you should not be able to edit associated data in each model edit page. As a side note, make sure all you created model classes are singular (in the /models/folder).
To edit multiple levels of association, it maybe as easy as setting the $recursive class member to 2 in each of the models where you want the edit page to have multiple levels of association. Let me know how this works out for you.
In response to your second issue.
Make sure your models have all the proper association. If you baked them they should include them but given your error it looks like they somehow weren't included. So in log_item.php you should have something like
var $belongsTo = array('SubProject');

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