Questions tagged [virtual-columns]

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how to add a query to postgres and have it show up as a table [closed]

I'm not sure what technology I need because I'm not a DBA, but I'm sure there's a good way to do this. I have a postgres database with this schema (top two tables exist): So I'm trying to add the 3rd ...
MetaStack's user avatar
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Intended use case for virtual columns with function-based index?

What is the intended use case for virtual columns with a function-based index? The reason I ask (novice): I've been exploring options for pre-computing columns in a table. For example, in a roads ...
User1974's user avatar
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Adding Virtual Column after column x is very slow

In our environment, we usually add and drop generated columns every now and then. There is a very large table in the database with more than 3 million rows and adding/removing column was extremely ...
Ali's user avatar
  • 195
2 votes
1 answer

Can not drop virtual column | ERROR 1054 (42S22): Unknown column in 'GENERATED ALWAYS'

I'm just running a command: optimize table some_table_name_here; But it results with: Table | Op | Msg_type | Msg_text db.some_table_name_here | optimize | note | Table does not support optimize, ...
iorsa's user avatar
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Convert rows into columns MySQL DataBase

I have two tables and I would like to generate a query relating the tables. Until now I have this query: SELECT Table1.*, table2.* FROM Table1 INNER JOIN table2 ON table2.FK_ID = Table1.ID but I ...
Silvestre Silva's user avatar
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Is it possible to alter normal column to virtual column in Oracle?

ALTER TABLE TAB_NAME ADD TEST_COL VARCHAR2(255); ALTER TABLE TAB_NAME MODIFY TEST_COL GENERATED ALWAYS as ('some_exp') VIRTUAL; Second script gives an error: Error report - ORA-54026: Real column ...
Raushan's user avatar
  • 113
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Column with Default value as Sum of TIMESTAMP

I have a table which has 2 columns ( JobDate , RecordTime) -------------------------------------- JobDate | RecordTime | SumCol -------------------------------------- 2019-07-20 | 2019-07-...
Amr Ahmed's user avatar
3 votes
3 answers

How to use column alias to calculate other column value

My query is SELECT (`house_rent`+`conveyance`+`medical`+`dearness`+`others_allowances`) AS earnings ,(`income_tax`+`pro_tax`+`emp_state_insu`+`absence_fine`+`others_deductions`) AS ...
Tanveer Jafri's user avatar
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Obtain virtual column formula with SQL

We want to update the condition of a virtual column and to minimize error posibilites we want to extract the exact function working today to add new parameters to take into account. I've firstly test ...
Jorge Vega Sánchez's user avatar
1 vote
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Does MySQL update indexes on virtual columns on tables that are being replicated from a master?

We use statement based bin log master-slave replication with MySQL 5.7. We use the slave for analytics and so add additional indexes and things not required on the master. I recently tried to add a ...
km6zla's user avatar
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"ORA-12899: value too large for column "V_UUID" (actual: 36, maximum: 4000)" when used to generate a Virtual column

I have the following function: CREATE FUNCTION UUID_AS_HEX(bytes IN RAW) RETURN CHAR DETERMINISTIC IS uuid CHAR(36); BEGIN RETURN REGEXP_REPLACE(bytes, '([0-9A-F]{8})?([0-9A-F]{4})?([0-9A-F]...
user avatar
2 votes
2 answers

Concatenate multiple columns into one column (,) separated [duplicate]

In SQL database that stores Images in a parcelImages table.Since each parcel can take part in multiple Images and each images can involve multiple parcels. I want to get each parcel having Image ...
Jubert's user avatar
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4 votes
1 answer

Oracle random number as default column value

I'm trying to create a table in OracleDB and assign random number to one of the columns as a default. I have this setup working in postgresql create table table_name ( column integer NOT NULL ...
KianTern's user avatar
4 votes
1 answer

How do MySQL 5.7 virtual columns differ from views?

Starting reading point: Running some tests with the most recent percona 5.7 they seem to work well. Explain plans ...
atxdba's user avatar
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6 votes
1 answer

Find columns referenced by virtual column expression

Does anyone know of any Oracle dictionary views that hold references of 'real' columns to virtual columns? For example lets say I have a table like this: create table t ( c1 varchar2(5) ,c2 as (c1 ...
Horrendo's user avatar
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Database engine that share a row among multiple tables

I'm wondering whether exists any database engine that can share cells or rows amongst many tables. For example: TABLE Customer ( CID: int Fullname: nvarchar(50) Age: int ) TABLE Group ( ...
hirikarate's user avatar
1 vote
2 answers

Constant values in columns

I have a SQL Server 2000 database used by our ERP system. There are many columns that always have the same value. A table row is really huge, potentially exceeding the maximum row size in SQL Server ...
Lorenz Meyer's user avatar
1 vote
1 answer

Creat Temporary Id in SQL Statement

I have a table id name 1 Alpha 2 Alpha 3 Beta 4 Charlie 5 Charlie I want to assign a temporary id at the run time in the SQL statement, So the desired result should be like myid name 1 ...
neeraj's user avatar
  • 260
4 votes
4 answers

Is (and if how) it possible in Oracle to "insert into <table> values <rowtype-variable>" if <table> has virtual columns

Here's a table create table tq84_virtual_test_without ( col_1 number, col_2 number, col_3 number, col_4 number, col_5 number ); with the rule that col_5's value is the sum of the other ...
René Nyffenegger's user avatar