![]() ![]() ![]() SHOW FULL PROCESSLIST while waiting for the FLUSH to complete (if there's a delay) will give you an idea of things that might get in the way of the rename operation, and you can safely KILL the flush if you need to. so it gives you a good test of what to expect and would be a good idea to run first, since it's typically going to make the actual rename operation slightly shorter by leaving less work for the rename to do. the table is automatically reopened by the next statement that accesses it. If you are able to execute a FLUSH TABLES table_name statement and have it return within a few seconds, that should serve as confirmation that the rename operation will complete in a similar amount of time, since it will need the same locks in order to remove any entries in the query cache related to the table, close the table, and clean up some internal structures like the table share object. The major delay you could see will come from other sessions preventing the RENAME from starting because the locks can't be immediately required. Note that's a link to the 5.0 documentation, and the 5.1, 5.5, 5.6, and 5.7 all have the same information. If you use ALTER TABLE tbl_name RENAME TO new_tbl_name without any other options, MySQL simply renames any files that correspond to the table tbl_name without making a copy. Renaming a table acquires a metadata lock on the table which requires that no statements be running against the table, no transactions have row locks, and no transactions are holding on to consistent snapshots of any MVCC versions of the table.Įither style of RENAME operation will attempt to acquire the metadata lock and subsequently-started statement impacting the table will block, waiting for the pending metadata lock. In the above syntax, we use alter table command to rename the existing table name. RENAME TABLE t1 TO t2 ĪLTER TABLE t1 RENAME TO t2 # as long as no other options to ALTER are also specified The rename table is one of the functionalities provided by Redshift. There are two statements that perform an equivalent operation. (It assumes that SQL Server supports an object level rename. The table should only be locked during the rename phase. It does not seem like a connectivity problem since the Import Wizard to Azure was fast.Renaming a table in MySQL does not require a temporary table. Rename OriginalTable to OriginalTableold Rename NewTable to OriginalTable Validate and Drop OriginalTableold The advantage here is that you do not hold a lock on the Original table for the duration of the operation. It does not seem specific to library since DBI and RODBC were slow uploading to Azure, but fast uploading to local databases. To me it almost seems like an Azure problem. RODBC library write speeds to Azure are fast (FALSE) Local (non-Azure) database write speeds as fast (TRUE)ĭBI library write speeds to Azure are fast (FALSE) there are numerous alternatives one can take when writing a PNG-supporting program. SSIS Import Wizard write speeds to Azure are fast (TRUE) Base color retro Lut Base color A Look-Up Table (LUT) is a file. Maybe I can list what I have done to get pointed in the right direction. Specify RENAME TO newname to rename the trigger. SET searchpath to repsales BEGIN ALTER TABLE orders RENAME TO oldorders. You can also use the DISABLE ALL TRIGGERS clause of ALTER TABLE to disable all triggers associated with a table. Distribution, or DIST keys determine where data is stored in Redshift. RODBC::sqlSave(channel = conn, dat = df1e3, tablename = "MY_DEV.speed_test1") How do you stop a trigger in Oracle Specify DISABLE to disable the trigger. You can't alter columns with default values. ![]() ![]() You can't decrease the size less than maximum size of existing data. You can also check if inserting records in 2 batch still sum to the same time. RODBC::sqlSave(channel = conn, dat = df100, tablename = "MY_DEV.speed_test1") In AWS Redshift is now possible to alter ONLY VARCHAR column but under these conditions: You can’t alter a column with compression encodings BYTEDICT, RUNLENGTH, TEXT255, or TEXT32K. You could try to measure if creating table and inserting records behave different. I am testing the same thing but with RODBC as opposed to DBI # 15.04 sec elapsed Hi I would open an issue, but I am struggling to know how to know which package is the issue. ![]()
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