Categories
Database Development

Storing data for machine learning in MySQL

I am currently in the process of developing a machine learning application, where my users can upload their own data to train models. Furthermore, the users must be able to extend their uploaded data with new data (append new data to it). I am in a bit of doubt when it comes to actually store […]

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Database Development

How to allow for ampersand in XMLtable()?

Starting with this Q&A, note that while this works: with data as ( select ‘Hallöle slovenĈina Hallöle slovenđina’ str from dual ) select a.str, b.str2 from data a, xmltable( ‘/’ passing xmltype( ‘<dat>’ || a.str || ‘</dat>’ ) columns str2 varchar2(4000) path ‘/dat’ ) b … this fails (note the addition of “AT&T and AT […]

Categories
Database Development

Storing data for machine learning in MySQL

I am currently in the process of developing a machine learning application, where my users can upload their own data to train models. Furthermore, the users must be able to extend their uploaded data with new data (append new data to it). I am in a bit of doubt when it comes to actually store […]

Categories
Database Development

Storing data for machine learning in MySQL

I am currently in the process of developing a machine learning application, where my users can upload their own data to train models. Furthermore, the users must be able to extend their uploaded data with new data (append new data to it). I am in a bit of doubt when it comes to actually store […]

Categories
Database Development

create trigger from sql to mysql

I have try to convert sql to mysql. because im watching tutorial on youtube and my database is mysql. here is my syntax on mysql CREATE TRIGGER ComputeTotal ON tblcart AFTER INSERT, DELETE, UPDATE on tblcart for EACH row set @total =@price * qty;

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Database Development

MYSQL Query Index Check

I have a table with the following structure; CREATE TABLE `operations_copy` ( `id` bigint(22) NOT NULL AUTO_INCREMENT, `date` datetime NOT NULL, `zoneId` int(11) unsigned DEFAULT NULL, `machineId` int(11) unsigned DEFAULT NULL, `shiftId` int(11) unsigned DEFAULT NULL, `statusId` int(11) unsigned DEFAULT NULL, `actualCycle` float(10,4) NOT NULL, `targetCycle` float(10,4) NOT NULL, PRIMARY KEY (`id`), ) ENGINE=InnoDB AUTO_INCREMENT=185538661 […]

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Database Development

Table design – one table or hundreds of small ones

I have the following problem: I have measuring devices, each one measure always the same quantities from the list of five different ones. Each device can measure different quantities from this list. I update the data only sometimes (once a month), but read them online based on time frames (no caching on app side). Every […]

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Database Development

3 additional varchar(32) keys and also updating them — too bad for performance?

I have a table in mind which basicaly would look like this: table1 ——– id bigserial autoincrement primary key, token1 varchar(32) unique not null, token2 varchar(32) unique not null, token3 varchar(32) unique not null [……..some other data ……] The tokens are UUIDs, just saved as varchar strings and without dashes. My client web app is […]

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Database Development

When should run Analyze table statement in mysql

Hello DBA’s i have also some question Why should we never run ANALYZE TABLE? How do I know for sure this table/db needs to be analyzed ? It seems that MySQL doesn’t store when the last time “stat” was updated ? Just for Example :- Assume i have queried mysql> show index from goods; +——-+————+———-+————–+————-+———–+————-+———-+——–+——+————+———+—————+ […]

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Database Development

Can I make a full export of a corrupted database?

I have a datafile with a corrupted block. Unfortunately I don’t have backup to repair with RMAN (BAD strategy, first the strategy delete the old backup and after make a new backup) Because this new corruption I can’t make a new backup with RMAN.. What happen if I make a full export of the database? […]