I finally discover the error. The problem is that the primary key constraint name is equal the table name. I don know how postgres represents constraints, but I think the error “Relation already exists” was being triggered during the creation of the primary key constraint because the table was already declared. But because of this … Read more
From http://www.sqlite.org/lang_createtable.html: CREATE TABLE IF NOT EXISTS some_table (id INTEGER PRIMARY KEY AUTOINCREMENT, …);
It is possible to create many tables (both managed and external at the same time) on top of the same location in HDFS. Creating tables with exactly the same schema on top of the same data is not useful at all, but you can create different tables with different number of columns for example or … Read more
There are many possible solutions: 1) Add distribute by partition key at the end of your query. Maybe there are many partitions per reducer and each reducer creates files for each partition. This may reduce the number of files and memory consumption as well. hive.exec.reducers.bytes.per.reducer setting will define how much data each reducer will process. … Read more
As id is the primary key, you cannot have different rows with the same value. Try to change your table so that the id is auto incremented: id int NOT NULL AUTO_INCREMENT and then set the primary key as follows: PRIMARY KEY (id) All together: CREATE TABLE card_games ( id int(11) NOT NULL AUTO_INCREMENT, nafnleiks … Read more
This feature has been implemented in Postgres 9.1: CREATE TABLE IF NOT EXISTS myschema.mytable (i integer); For older versions, here is a function to work around it: CREATE OR REPLACE FUNCTION create_mytable() RETURNS void LANGUAGE plpgsql AS $func$ BEGIN IF EXISTS (SELECT FROM pg_catalog.pg_tables WHERE schemaname=”myschema” AND tablename=”mytable”) THEN RAISE NOTICE ‘Table myschema.mytable already exists.’; … Read more
I tried all the solutions here, but only this parameter innodb_strict_mode = 0 solved my day… From the manual: The innodb_strict_mode setting affects the handling of syntax errors for CREATE TABLE, ALTER TABLE and CREATE INDEX statements. innodb_strict_mode also enables a record size check, so that an INSERT or UPDATE never fails due to the … Read more
“MySQL retrieves and displays DATETIME values in ‘YYYY-MM-DD HH:MM:SS’ format.” This is from mysql site. You can store only this type, but you can use one of the many time format functions to change it, when you need to display it. Mysql Time and Date functions For example, one of those functions is the DATE_FORMAT, … Read more
http://wiki.postgresql.org/wiki/Transactional_DDL_in_PostgreSQL:_A_Competitive_Analysis provides an overview of this issue from PostgreSQL’s perspective. Is DDL transactional according to this document? PostgreSQL – yes MySQL – no; DDL causes an implicit commit Oracle Database 11g Release 2 and above – by default, no, but an alternative called edition-based redefinition exists Older versions of Oracle – no; DDL causes an … Read more
CREATE TEMPORARY TABLE IF NOT EXISTS table2 AS (SELECT * FROM table1) From the manual found at http://dev.mysql.com/doc/refman/5.7/en/create-table.html You can use the TEMPORARY keyword when creating a table. A TEMPORARY table is visible only to the current session, and is dropped automatically when the session is closed. This means that two different sessions can use … Read more