Questions tagged [datatypes]

Specifies the type of data being stored (string, date, numeric, etc).

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why some one will use approximate data types for sales

I was messing around with Kartris online shop and I was reading this definition for a product version(you have basic information of a product in one table and many versions of products wich can have ...
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DECIMAL and NUMERIC datatype in Postgres [closed]

what is the use of decimal and numeric datatype in postgreSQL. As per the reference the following is the explanation given to these datatypes. decimal,numeric --> It is a user specified precision,...
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force SQLite view column type affinity

Using SQLite 3, I have some view columns which are defined with an expression, and so have no type affinity. Is it possible to define them in a way that forces them to have a certain type affinity? ...
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1answer
506 views

Effect of changing data types with row compression enabled

The company I work for has a couple of SQL Server databases with tables containing +- 500.000.000 rows. We are running Enterprise editions of SQL Server 2008R2 and 2014. Big data types When I look ...
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2answers
184 views

What data type are the numbers in a SQL Server statistics object?

Specifically I'm most interested in: The 'All density' number in the density vector Numbers in the histogram E.g. are they floats / decimals? What precision / scale / length do they have? The ...
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1answer
727 views

Low cardinality fields: integer or string

A Ticket has the statuses: new in_progress on_hold closed I could make ticket.status a string (on_hold) or an unique int(2). It is indexed. Int pros: smallest size in index Int con: low clarity ...
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1answer
79 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 ...
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Do relational databases typically understand '1' and '0' as booleans?

I'm working on a code library that helps users build database searches from form inputs (a layer on top of an ORM). I want it to be compatible with most relational databases. I currently have a ...
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1answer
1k views

Surprising results for data types with type modifier

While discussing a recursive CTE solution for this question: Get the last 5 distinct values for each ID @ypercube stumbled across a surprising exception, which lead us to investigate the handling of ...
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2answers
2k views

MySQL database column to Store Phone numberss

What is the best approach to store Phone Numbers (Mobile Number and Office Number) in MySQL table? Users may have MobileNumber (CountryCode and MobileNumber) and Office Number (CountryCode, ...
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What is the optimal data type for an MD5 field?

We are designing a system that is known to be read-heavy (on the order of tens of thousands of reads per minute). There is a table names that serves as a sort of central registry. Each row has a ...
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5k views

Why 't' and 'f' instead of TRUE and FALSE

Why does PostgreSQL return 't' and 'f' instead of TRUE and FALSE? The documentation itself advises us to use TRUE and FALSE when inserting boolean values or making comparisons, but returns a ...
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1answer
44 views

Advantages of POINT over DOUBLE for distance queries?

I'm about to start an application that will need a simple distance query to order results. After some search I've discovered some functions that seems to do this work pretty easily without needing ...
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1answer
1k views

Storing variable length arrays of doubles in MySQL without loss of information

I am trying to store variable length arrays of C++ doubles into a MySQL database. I was initially storing each value in the array as a row of the form: `pv_name` varchar(60) NOT NULL, `time_stamp` ...
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1answer
3k views

Oracle NVARCHAR2(4000) with AL32UTF8 possible?

I thought, through reading items here and elsewhere, that if my Oracle database NLS_CHARACTERSET is set to AL32UTF8, I can have a column of type NVARCHAR2(4000), but when I try to create it, I get SQL ...
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1answer
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VARCHAR2 should perhaps be DT_WSTR when working with SSIS against a Oracle Database?

When using SSIS with Oracle database, it seems to always assume that a VARCHAR2 maps to a DT_STR. However, if my Oracle encoding is set to AL32UTF8, I should be able to store any unicode character in ...
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1answer
1k views

Array of strings when updating a field

Unintentionally discovered that following query works in PostgreSQL: UPDATE "sometable" SET "somefield" = ('string1', 'string2') WHERE "id" = 1; I'm passing an array of strings to field and the ...
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1answer
3k views

Add column with a sum total to crosstab() query in PostgreSQL 9.0

Following on from my previous question: Creating crosstab() pivot table in PostgreSQL 9.0 I managed to create a pivot table for ageband using the crosstab() function. I can use this to either create ...
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1answer
984 views

Do fixed-width rows improve PostgreSQL read performance?

I have a table articles: Table "articles" Column | Type | Modifiers | ...
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113 views

MATLAB® export double numbers into PostgreSQL by `datainsert` (of Database Toolbox)

How is it possible to pass double numers into numeric postgreSQL columns from MATLAB? Here the list of matlab data: var1 197x1 cell var2 197x1 double var3 197x2 double var4 197x2 double ...
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1answer
137 views

SQLite Data Types In Context of Disk Space

I would like to better understand which data types in SQLite take up more disk space. I've looked through official documentation but could not find anything in context of storage space. Any guide ...
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1answer
370 views

Modulo operator with nonintegers - unexpected results

MySQL 5.5.32, Oracle 11g MySQL returns strange results for queries involving mod() with noninteger moduli. Why is this? I have a column defined thus: +--------+--------------+------+-----+---------+...
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2answers
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How to best store a timestamp in PostgreSQL?

I'm working on a PostgreSQL DB design and I am wondering how best to store timestamps. Assumptions Users in different timezones will use the database for all CRUD functions. I have looked at 2 ...
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1answer
14k views

SELECT in trigger function in two tables

My table and trigger in PostgreSQL 9.4.3 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit: CREATE TABLE measurements ( measurement_id SERIAL PRIMARY KEY NOT NULL, ...
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1answer
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Slow window function query with big table

I'm doing some performance testing on a new DB design on PostgreSQL 9.4rc1 and I'm seeing some pretty slow queries using window functions. Here is my table setup: CREATE TABLE player_stat ( ...
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1answer
4k views

Grant execute on specific type in Oracle

I have created a package and defined a type for collections as follows: create or replace package <schema>.<package> as ------------------------------------- type <type> is ...
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1answer
3k views

pg_restore warning column X has type unknown

I'm doing a dump from PostgreSQL 9.1 and restoring on PostgreSQL 9.4 and getting this warning pg_restore: WARNING: column "foobar" has type "unknown" DETAIL: Proceeding with relation creation ...
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1answer
404 views

What is the best SQL Server field type to cast to when storing a UNC path stored in a sql_variant field?

What is the best choice of field type to cast to when storing a UNC path in a sql_variant in Microsoft SQL Server 2008? It appears that I could store up to 4000 characters according to Microsoft ...
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38 views

Uninitialized values: ignore or set?

From the implementation point of view for a database, is it preferable to handle optional form fields by setting to some default value (e.g. false, 0, "", etc.) or just ignore such fields (do nothing ...
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Is there a way to determine if a postgres function depends on a user-defined type?

I am writing a Ruby script to handle functions and user-defined types in Postgres. I want to make sure, that before a function is created in the database, if it uses a user-defined type, than this ...
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1answer
7k views

MySQL loading NULLs in numeric columns

MySQL 5.6.23, InnoDB I am loading tables from character delimited text files using the LOAD DATA INFILE commnd and I would like every field with a \N, which is the NULL character in this setting, to ...
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1answer
2k views

Storing phone number in E.164

TLDR; If I store a phone number in MySQL(or any DB with equivalent constraints), would the correct format be E.164 values into a VARCHAR(32) field? Have been reading up on format/storage of ...
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1answer
127 views

Is there a data type in MySQL similar to varchar(n) that not allow numbers or special characters in it?

Is there a data type in MySQL similar to varchar(n) that not allow numbers or special characters in it?
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2answers
6k views

SQL Server BigInt vs Decimal

I need to choose a data type for SQL Server( BigInt vs Decimal) on the basis of performance and querying (10 digit number)
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1answer
761 views

Mysterious inequality behavior when comparing date strings

Can someone explain this mysterious Postgres behavior? I'm performing the following queries at the psql command line. mydb=> select '20150526' > '2015-05-25'; -[ RECORD 1 ] ?column? | t mydb=&...
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1answer
670 views

PostgreSQL bytea vs smallint[]

I'm looking to import large (100Mb -- 1 GB) multi-channel time-series data into a PostgreSQL database. The data comes from EDF format files that chunks the data into "records" or "epochs" of typically ...
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2answers
3k views

change column type from string to numeric

so I have a table with 5.2 million records. 3 columns in this table are for salaries. Those column are currently stored as string and I'd like to change the data type to numeric (I understood while ...
3
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2answers
279 views

Overwhelmed with Sensor Data - Excel to SQL Server fails

I'm managing a lot of sensor data and need to do charting, smoothing, stats over time on the data. Currently I import the data from flat files using VBA to do ETL into Excel. The format of the data ...
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3answers
3k views

Unknown returned type in PostgreSQL query

The following query works: SELECT a, b FROM unnest(ARRAY[(1,2), (3,4)]) AS t(a integer, b integer); a b _ _ 1 2 3 2 However, I wasn't able to use a different column type such as varchar(255): ...
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1answer
149 views

Is there any point in specifying the precision and scale of a number for a foreign key?

I am running Oracle 11gR2 11.2.0.3. I have two tables: table1 contains a column named SUBJECT_ID, whose datatype is NUMBER(7,0) (numbers range from 13 to 48480) table2 contains a a column named ...
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1answer
4k views

PostgreSQL column for year

I want to save the year in a PostgreSQL database - just the year. How should I create this field? There is a lot of information out there how I can extract the year from a date field, but not on how I ...
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1answer
6k views

Rich text: VARCHAR, TEXT or BLOB in MySQL

Question: In my web application (php/MySQL) I will be saving rich text. This may be anything from a couple words to several pages length essay. I’m sure I could get away with using VARCHAR, TEXT or ...
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2answers
750 views

Find and return items based on matching strings across 17 tables

I must start by saying that I am at best a sql novice. I am doing some data analysis and consolidation for my company and need to find if items match across any of the tables. The info in the tables ...
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2answers
2k views

Why is Oracle's number datatype so HUGE? and why do I seem to have no alternatives?

Oracle has a favorite numerical class called NUMBER. It is a 22 byte value that just seems ludicrous in an index. I have some values that would easily fit in a 6 byte integer and would therefore fit ...
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2answers
528 views

Query that was working on MySQL is not working on PostgreSQL

I had the following query (with bin_number being a string) which was working on MySQL 5.5: Postgres - was working on MySQL and doesn't work on PostgreSQL SELECT "menu_items".* FROM "menu_items" ...
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1answer
83 views

Warehouse Database Design Question

Apologies if this has been answered previously but I have been unable to get a specific model to work. I have a database table that needs to store some very basic info for a reporting system. The ...
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1answer
2k views

Cannot SUM datetime field in SQL Server migrated from Access

I am new here and am new to SQL Server (Express). I used the SSMA tool and it converted Access date/time fields to datatime2. The data contains duration data so there is no need for a date. I want to ...
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2answers
651 views

Moving data from table with VARCHAR(50) fields to table with numeric fields increases table size

I want to understand why migrating data in a table with all VARCHAR(50) fields to a table with optimized smaller types caused the new table (containing 61,065,164 rows) to be 4.46 GB, which is larger ...
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1answer
5k views

PostgreSQL SELECT primary key as “serial” or “bigserial”

I've meshed together a way to determine what the data_type is as in the data_type you use in the syntax when creating a new table based off of the PostgreSQL wiki page. If there is something wrong ...
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2answers
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How can I store latitude and longitude without PostGIS?

I know there are similar questions on here that have been answered but unfortunately none of them work for me. I am hacking my way through creating a page which will display multiple locations on a ...