Questions tagged [information-schema]
information schema : ODBC standard Views of RDBMS MetaData
1
vote
1answer
23 views
Why is the value of NUMERIC_SCALE column in INFORMATION_SCHEMA.COLUMNS table for DATA_TYPE='double' NULL?
I have created a column whose data_type is DOUBLE.
alter table my_table add column my_column double;
When I queried about this column in information_schema.COLUMNS table
I found that the ...
0
votes
0answers
23 views
Why information_schema.columns is_nullable is varchar? [duplicate]
Looking for all columns "not null" is very useful sometimes, right?
So, I'm thinking on "why on earth the 'is_nullable' columns from information_schema.columns is varchar, not boolean?"
On first ...
3
votes
2answers
133 views
GRANT SELECT ON SEQUENCE succeeds, but to no effect?
I am trying to grant select access to sequences from one user/role to another. There are no errors when I run the command but once run, the second role is unable to view the sequences. I have run the ...
1
vote
0answers
71 views
Interesting Database Designs for Product Catalogue including Recursive
I am doing some work for a client and they are creating a database of products of which I need to consume product data when it's created and updated to store in a third party service and then present ...
0
votes
2answers
79 views
Information_Schema on oracle?
I'm a SQL Server DBA, and I like to mess around with Oracle here and there.
I can see with select * from information_Schema.columns everything about a table (everything that I need now).
Is there a ...
1
vote
3answers
39 views
Does MariaDB 5.5.56 have INFORMATION_SCHEMA.INNODB_METRICS?
I'm trying to debug why I don't have INFORMATION_SCHEMA.INNODB_METRICS. I'm uncertain because I see it in the MySQL 5.5 reference glossary: https://dev.mysql.com/doc/search/?d=10&p=1&q=...
1
vote
1answer
346 views
Is it possible to concatenate query results to form a new query?
I have now:
SELECT TABLE_SCHEMA ,
TABLE_NAME ,
COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME = 'NNN';
This gives me several hundreds of rows, because several tables contain ...
1
vote
1answer
75 views
Information_Schema.Tables reports different result in MySQL 5.5 and MySQL 5.7
I have started testing some MySQL 5.7 databases to replace our ageing 5.5 Databases, and there seems to be a significant change in the way the information_schema.tables Table records the data size.
I ...
0
votes
1answer
49 views
Query to identify bad indexes and/or no indexes (on tables with lots of records) takes 4-6 minutes to execute
Query:
SELECT Concat(t.table_schema, '.', t.table_name),
t.table_rows,
snu.non_unique,
smax.cardinality,
( t.table_rows / Ifnull(smax.cardinality, 1) ) AS
...
1
vote
1answer
169 views
Where in pg_catalog is the database or catalog information stored about relations?
When I query a table like information_schema.tables
SELECT
table_catalog,
table_schema,
table_name
FROM information_schema.tables;
I get a result like this,
table_catalog | table_schema ...
1
vote
1answer
287 views
How do I list all columns for a specified table that begin with a specific string [duplicate]
How to select all the columns whose names begins with "img" from a PostgreSQL table?
I wrote that, but doesn't work
select 'img%' from mytable
7
votes
1answer
876 views
Why does information_schema have “YES” and “NO” character strings rather than booleans?
I was taken by surprise to find that the is_nullable column for this query is typed as character varying (3) rather than boolean:
select
column_name,
data_type,
is_nullable
from
...
0
votes
0answers
23 views
MySQL - Where i can find Innodb_history_list_length variable in new versions of mysql
MySQL version:
percona-server-server-5.7 5.7.21-20-1.stretch
What i get in new version of MySQL when i try execute the query:
SELECT count FROM information_schema.innodb_metrics WHERE name = '...
1
vote
2answers
169 views
SQL Server 2016 Temporal tables metadata
Is there any way to get metadata (information scheme) information about temporal table feature for the table, like:
Is DATA_CONSISTENCY_CHECK TURNED ON OR OFF
What name of history table
Is ...
0
votes
0answers
139 views
`SELECT` on `information_schema`.`tables` returns less rows if I `SELECT` the `CREATE_TIME`
Context
We have a MySQL 5.6.28 server with a lot of schemas on it. After a crash, we have some schema where a table x exists, and other schemas where it's an orphan table.
On a non-corrupted schema, ...
1
vote
1answer
34 views
Information_schema appearing in slow_log
I am finding that my information_schema keeps running this query
SELECT engine, COUNT(*) as n FROM information_schema.tables WHERE engine is not null GROUP BY engine
Which seems to always appear in ...
2
votes
1answer
3k views
postgres system catalog query columns from table
I am building an integration test against an app that provisions a database for a user. The User created for it is not a super user, and does not have access to schema_information.tables because when ...
1
vote
1answer
1k views
How do I query INFORMATION_SCHEMA.COLUMNS on Amazon RDS?
I received a list of column names from another team. To ensure all field column names are valid inside a specific schema, I put them into a temporary table. I'm now wanting to see if they exist. When ...
1
vote
0answers
66 views
mariaDB tables create_options clear
I have MariaDB 10.2.9 on Centos7 with ~60 tables. I listed the table's create_options from information_schema.tables:
SELECT TABLE_NAME, TABLE_TYPE, CREATE_OPTIONS
FROM information_schema.tables
...
0
votes
1answer
106 views
MySQL - “CREATE_OPTIONS” in “information_schema.tables”?
I have a MySQL 5.7.16 Enterprise running on a Centos 6 machine with InnoDB as the default storage engine. I have around 300 tables in which around 90 are "list" partitioned.
I have the option ...
1
vote
2answers
470 views
Unable to join on conrelid and confrelid columns in pg_constraint
I'm trying to get a list of foreign key constraints in the following form:
pk_table | pk_col | fk_table | fk_col
without using pg_get_constraintdef (which would force me to resort to string ...
1
vote
0answers
37 views
error codes in information_schema
Is there a view or table or relation in information_schema with the error codes or exception names?
My question is in STANDARD sql or in PostgreSQL.
0
votes
2answers
3k views
How to get the next auto-increment id in MySQL?
How to get the next id in mysql to insert it in the table ?
INSERT INTO payments (date, item, method, payment_code)
VALUES (NOW(), '1 Month', 'paypal', CONCAT("chaminda", id))
-1
votes
0answers
515 views
How does the query table_schema=database() work?
In the query
select table_name from information_schema.tables where table_schema=database();
as I understand; the information_schema.tables references to all the tables in the information schema ...
1
vote
1answer
584 views
Tables in one of my schemas are not listed in INFORMATION_SCHEMA.TABLES. What can be the reason?
I have three schemas in my SQL Server database, but when I query over INFORMATION_SCHEMA.TABLES only tables that belong to two of the schemas are listed. Tables in the third schema are not listed. ...
0
votes
1answer
41 views
How to locate all the tables that have a field named username
Is there a way in PhpMyAdmin to do a SQL search for all tables, that have a fieldname username in it?
I am trying to help a friend that has a database with over 1,000 tables in it.
He needs to find ...
1
vote
2answers
352 views
How do I navigate PostgreSQL documentation to find a list of all functions that work on a specific type?
Let's say I want to find a list of functions that can work on jsonb, what is the most effective way to do this from the terminal without using google? Assuming only access to
man pages
psql
...
1
vote
1answer
452 views
MySQL - huge Dictionary memory allocated
Our MySQL 5.5.38 servers have 1000-3000 InnoDB databases each (with about 100 tables each). All data is in single file. Most of DBs are active. While it's expected that information schema should be ...
1
vote
0answers
67 views
Schema transfer of SP does not update information_schema.routines.routine_definition / object_definition?
After a transfer of an SP from one schema to another, the information_schema.routines.routine_definition and object_definition() still show the original schema.
create schema SchemaA;
go
create proc ...
3
votes
2answers
1k views
count null values of table from information_schema tables
Is there any way to count null values in a column by using information_Schema tables? EG:
SELECT table_name, table_rows
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA ='myschema'
and ...
0
votes
1answer
117 views
where are the infos from 'SHOW CREATE TABLE' coming from? It's not INFORMATION_SCHEMA
Quote from MariaDB 10.2 CHECK and DEFAULT clauses:
Another limitation is that CHECK metadata are not accessible via the
INFORMATION_SCHEMA. The only way to find out if a table has CHECK
clauses ...
1
vote
2answers
35 views
Different services using different port pointing to same datadir folder
Let say I have already installed service MySQLa with mysqla.ini (port number=3306) setting and datadir folder in ...\data
Is it possible then, I install another service MySQLb with mysqlb.ini (port ...
2
votes
1answer
499 views
Is there a way to get SQL Server capcity constraints dynamically
I have some code which creates database tables dynamically, and I want to ensure that people don't try to do things that result in me trying to create a table with more columns than what SQL Server ...
1
vote
0answers
30 views
What are all the catalogs that RDBMS have to implement to be ANSI compliant?
My goal is to be able to go into any environment, and immediately get a general idea of what is going on in a database server. I know most RDBMS implement INFORMATION_SCHEMA, which has a lot of useful ...
1
vote
2answers
2k views
Query to retrieve index details for a particular column in all tables
There is a column created_at in most of tables.
I would like to get the details if that field exists in the table and it is not indexed.
Is there any thing can be done with the information_schema to ...
0
votes
1answer
6k views
how to update information_schema.tables in mysql [duplicate]
i have a table A and i want to update the creation time of this table.
I understand i cant simple update ( using update query) as it is not any table.
Is there any way i can update it.
for example ...
1
vote
1answer
87 views
What happens to mysql information_schema after switching to innodb_file_per_table?
We're switching our mysql dev deb instance to innodb_file_per_table and moving the data dir onto another mounted drive so we can free up space on our dev box.
We've backed all our dbs up and about to ...
7
votes
1answer
783 views
What permissions are required to return rows from information_schema.schemata?
In postgres (I'm on 9.3.4) what permissions are required to return rows for
select * from information_schema.schemata
The 9.3 documentation says "are owned by a currently enabled role". Does that ...
0
votes
1answer
311 views
MariaDB: calculate the reads/writes ratio in percent
I found a blog post howto calculate the reads/writes ratio in percent.
I receive NULL values in our env.
> SELECT @total_com := SUM(IF(variable_name IN ('Com_select', 'Com_delete', 'Com_insert', '...
2
votes
1answer
972 views
Amazon Aurora CREATE_TIME in INFORMATION_SCHEMA.TABLES is NULL
We are running an Amazon Aurora database that emulates MySQL 5.6.10. The CREATE_TIME in SHOW TABLE STATUS and INFORMATION_SCHEMA.TABLES is consistently NULL for all our tables.
Is this a bug, a ...
2
votes
0answers
215 views
Get the name of the table column referenced by a (auto updatable) view column (PostgreSQL)
Given the folowing view definition
create or replace view projects as
select id, client_id as clientId from data.projects
Is it possible, knowing the view name and the view column to get the name of ...
1
vote
1answer
614 views
Does INFORMATION_SCHEMA always contain up-to-date metadata?
This query prints the size (in terms of data and indexes) of the tables in mydatabase:
SELECT table_name "Table name",
round(((data_length)/1024/1024),2) "Data size",
round(((index_length)/1024/1024)...
0
votes
1answer
156 views
Query other database's INFORMATION_SCHEMA tables
I have a shared database that stores procedures for all the other databases on the same server. This helps maintain one instance of a procedure rather than copying it across all databases. As long as ...
4
votes
1answer
7k views
INFORMATION_SCHEMA.GLOBAL_VARIABLES alternative in 5.7? More info about show_compatibility_56
mysql> SELECT * FROM GLOBAL_VARIABLES;
ERROR 3167 (HY000): The 'INFORMATION_SCHEMA.GLOBAL_VARIABLES' feature is disabled; see the documentation for 'show_compatibility_56'
mysql> SELECT VERSION(...
0
votes
1answer
589 views
How do I join information schema to the table's data?
I need to join a table using it's column name from the INFORMATION SCHEMA. Is this possible?
I actually found another way to work around it. I am using Innodb. For the structure it's kind of ...
1
vote
1answer
2k views
INFORMATION_SCHEMA.VIEW_TABLE_USAGE only shows tables from the same catalog
I'm working with a database that has many cross-database views. While INFORMATION_SCHEMA.VIEWS lists all these views, INFORMATION_SCHEMA.VIEW_TABLE_USAGE and INFORMATION_SCHEMA.VIEW_COLUMN_USAGE do ...
0
votes
1answer
51 views
Working with PostgreSQL information_schema and tables (with same names, in different schemas) whose names start with a number
I'm needing to work with tables whose names start with numbers. For example, in the crs_1973 schema there is a table called 2015_04_21. I know that when the table name is made up of numbers, I must ...
1
vote
0answers
70 views
MySql - view out params of stored procedure when it selects from table
I have stored procedure:
DELIMITER //
CREATE PROCEDURE prcGetFemaleUsers()
begin
select firstName, lastName
from tblUser
where gender = 'female';
end //
DELIMITER ;
How can I get types ...
9
votes
4answers
24k views
Calculate row size and max row size for a table
Problem:
Is there any way of calculating number of bytes occupied by the table creation, i know that you can get some information from information_schema.tables but that information is not accurate ...
1
vote
0answers
15 views
Query INFORMATION_SCHEMA for list of indexes [duplicate]
How does one query INFORMATION_SCHEMA in a standards-compliant database such as Postgres to obtain a list of all indexes in one database/catalog?
