I make a simple test use ignite and mariadb,
same data in ignite and mariadb about 100000 line,
and then use same select statement to load data, find ignite is slower than mariadb lots of sql.
that's why? i think ignite is more faster than relation db.
have seem the article, enter link description here.
learn a more ignite and rmdb, i think ignite is great well in large data.
Related
As far as I can tell both commands create a clone of the db in SQLite format in the end, so why are there two commands to do this?
.backup uses the SQLite Backup API to create a clone atomically, even if the database is in use.
.clone copies the database by just running SQL commands. As far as I can tell, no transactions are done on the source database when doing the clone, so it has a chance of getting partially updated data mid way through the clone.
Trying to figure out what are the alternatives in Snowflake for Teradata BTEQ's and TPT(Import/Export)
In Teradata BTEQ's, which are run for an Enterprise using scheduled jobs on UNIX/LINUX , we have the flexibility of writing different SQL's in a sequence.
What alternative we have in Snowflake?
I'm not overly familiar with Terdata but based on this overview of beteq I would say that the Snowflake equivalent is probably the SnowSQL CLI. In terms of import/export the SnowSQL CLI can be used to upload data via the PUT command.
I have a website solution that uses on SQLite database for each tenant account. Without going into much depth about why we chose this solution, we chose it due to SQLite support on distributed/offline systems.
All databases are manipulated using the same PHP file structure. I wish to update the database version iteratively for all accounts so that they are all at the same version number.
I have a script that loops over each, and can use either PHP(Yii) or the shell to execute queries.
I would like to wrap the manipulation to each database in a transaction. It appears as though DDL commands may already be auto-commit in nature.
Question: How to accomplish a SQLite DB upgrade which, if it fails, will report a failure? Using that report, I could prompt the system to re-attempt or report an error to an admin. Ideally, I would like to wrap the whole upgrade in a transaction to prevent inconsistencies, but I'm fairly certain that this is not possible.
One thought I had was to backup the database temporarily during upgrade, and delete it on success.
As CL stated in the comments, DDL is fully transactional in SQLite. So, for each database in our system, we wrap it in a transaction, and it executes atomically. We leverage the application to ensure that all databases upgrade successfully if any fail during upgrade.
I have been developing locally for some time and am now pushing everything to production. Of course I was also adding data to the development server without thinking that I hadn't reconfigured it to be Postgres.
Now I have a SQLite DB who's information I need to be on a remote VPS on a Postgres DB there.
I have tried dumping to a .sql file but am getting a lot of syntax complaints from Postgres. What's the best way to do this?
For pretty much any conversion between two databases the options are:
Do a schema-only dump from the source database. Hand-convert it and load it into the target database. Then do a data only dump from the source DB in the most compatible form of SQL dump it offers. Try loading that into the target DB. When you hit problems, script transformations to the dump using sed/awk/perl/whatever and try again. Repeat until it loads and the results match.
Like (1), hand-convert the schema. Then write a script in your preferred language that connects to both databases, SELECTs from one, and INSERTs into the other, possibly with some transformations of data types and representations.
Use an ETL tool like Talend or Pentaho to connect to both databases and convert between them. ETL tools are like a "somebody else already wrote it" version of (2), but they can take some learning.
Hope that you can find a pre-written conversion too. Heroku one called sequel that will work for SQLite -> PostgreSQL; is it available without Heroku and able to function without all the other Heroku infrastructure and code?
After any of those, some post-transfer steps like using setval() to initialize sequences is typically required.
Heroku's database conversion tool is called sequel. Here are the ruby gems you need:
gem install sequel
gem install sqlite3
gem install pg
Then this worked for me for a sqlite database file named 'tweets.db' in the current working directory:
sequel -C sqlite://tweets.db postgres://pgusername:pgpassword#localhost/pgdatabasename
PostgreSQL supports "foreign data wrappers", which allow you to directly access any data source through the DB, including sqlite. Even up to automatically importing the schema. You can then use create table localtbl as (select * from remotetbl) to get your data into the actual PG storage.
https://wiki.postgresql.org/wiki/Foreign_data_wrappers
https://github.com/pgspider/sqlite_fdw
I need to export the data of a SQLite database and import this data to another SQLite database. But the two databases have different schemas.
Does exist an open source tool that can help me doing that job?
The only opensource tool that i know is opendbcopy that i'm using for migrate from a database server to another and also for a similar kind of job that you want to do with SQLite but i've done it with PostgreSQL.
However opendbcopy is JDBC compliant and can connect to every database that have a JDBC driver, so you can try, also if the schema is not the same you can use the column mapping feature :
In addition i know also a good commercial alternative (that is easier to use) that is ESF Database Migration Toolkit .