Transaction log is a list/history of modification executed by a database management system to guarantee ACID properties over crashes or hardware failures.

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Does it make sense to use full recovery if the data and log files are on the same HD?

We have a database that was set up to use full recovery and my guess is that the reasoning was only to prevent data loss if a failure happened between full backups. We make daily full backups of the ...
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2answers
818 views

What is the undo pass that SQL Server does during a RESTORE WITH STANDBY operation?

It's my understanding that SQL Server generates undo files when applying a restore to a database using the RESTORE WITH STANDBY. From the MSDN documentation (Emphasis mine): The standby file is ...
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3answers
5k views

Difference between Full backup and Copy-only full backup

I saw in this link that full backup does not truncate the log. So what is the difference between full backup and copy-only full backup? For the log backup there is copy-only backup which prevent the ...
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Transaction Log maintenance when switching to Simple Recovery

Background: I recently inherited 50+ SQL Servers with 450+ databases. The nightly backups are roughly 8TB and, needless to say, we're using more disk space than we'd like. All of the databases are ...
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2answers
1k views

SQL Server 2008 Query Saved in Logs?

Every time I create a query and run it to create a report I save the query in my Projects folder in case I have to rerun the query in the future or if I have to modify it for any reason but it seems ...
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Question about logging architecture

I understand that when (for example) an update is issued, the data pages are first read into the buffer pool, locks are acquired and changes are written out to the log file in the buffer, then the log ...
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Multiple Transaction Log files and performance impact

So I've gotten into an argument with several people regarding the number of transaction log files a give databases should have. I've seen several post saying you should only have 1 transaction log ...
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2answers
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Reducing high VLF count

I have been using Brent Ozar's sp_blitz script to review our database setup and have found that the VLF count is high (13562!) on the primary DB since changing to Full recovery model. I ran a full ...
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1answer
259 views

Does blocking always mean open transaction?

This may seem a bit dull question but does blocking always mean that there is open transaction and that may cause transaction log grow to infinity because open transaction prevents log truncation ...
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1answer
93 views

Storing Tlogs and data files on the same drive

I'm looking for some clarification of various things I've read. I understand it to be best practice to store your transaction logs on a separate drive (spindle) than where you MDFs and NDFs are ...
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3answers
683 views

When are Archived Redo Logs generated?

We have an instance in Oracle 10g. Only one schema is used for a web application (Internet-facing), which is only user for reading information, no adding or modifying data. The rest of schemas are ...
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4answers
509 views

SQL Server restore from transaction log

In SQL Server 2005, if you have a database with no backup - but it is running in full recovery mode - is it possible to "roll back" some deletes? If yes - how?
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1answer
394 views

How to pinpoint root cause of excessive log file growth

The log file stays pretty small (~500MB) until about 11PM, and at that point it begins growing until no disk space is available. The log file reached it's maximum size at 12:39AM, so the growth took ...
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2answers
595 views

How large will the Transaction Log backup be?

I encountered a production database of 12 GB with a log of 90 GB. Full and differential database backups are made with a third-party backup tool, but no one is backing up the transaction log so it got ...
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2answers
4k views

How to monitor SQL Server data and log file growth?

I'm trying to find a way to monitor data and log file size from SQL Server databases (within an SQL Server instance). I would not want to use third party tools, but simply pure SQL or PowerShell. I ...
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1answer
545 views

Does creating / updating statistics have an impact on the transaction log?

Does creating or updating statistics, assuming on a large table, create significant (or at all) transaction log churn? I would think not as it does not change the underlying data or structure. If it ...
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3answers
132 views

Log File Management - Space on Disk

At our organisation we have several non-Production environments where Developers run free and wild with TSQL code and databases. The DBA team do not normally monitor or maintain them. Recently several ...
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1answer
818 views

How to troubleshoot db/app latency during transaction log backup

I have an application that uses a SQL server (2008 R2) database and we are periodically having performance problems with the application and it coincides with our 15-minute transaction log backups. ...
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2answers
1k views

Is this procedure to Failover to Logshipped secondary and Fail back again procedure correct?

I have a primary database in Amsterdam (AMDB), and a secondary in London (LNDB). I want to fail over from AMDB, to LNDB and then back again, without having to make another full backup (because the ...
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1answer
95 views

Database is happily available even during log growth?

I’ve been creating a process to go through all our databases and analyze the log structure, backup, shrink, and resize appropriately taking operational requirements and VLF sizing/amount into account. ...
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1answer
76 views

Tail Log backup when doing a restore?

Typically when doing a restore of a DB from a production server to a non-production server I will use the WITH REPLACE option as when I forget I get an error about the tail log not being backed up. ...
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2answers
565 views

Missing Transaction log in chain, Possible to skip

We have had one of our clients SQL Servers crash and need to restore it to the most recent possible time. We have a full backup from Monday and transaction logs that run every hour up until this ...
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1answer
52 views

Implement Log Shipping in prod env

We have a 3.5 TB DB which is already involved in log shipping to two different servers, as one will be in restore sate only and one will be in stand by mode which helps for reporting needs. All three ...
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2answers
466 views

Time to apply transaction logs: does it matter how many logs?

When restoring from a backup in SQL Server, the procedure is to restore the .bak file and then apply any .trn files since the last full backup. Does it make a difference how many .trn files there ...
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2answers
209 views

SQL Server transaction log - shrinking and reattaching

I have the next scenario in SQL Server 2008: one big database (production DB). I want to backup this db then restore it on another server. Then I do some delete operation from some big tables. After ...
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2answers
214 views

Will removing a 2nd log file break log shipping?

We have a large database 200GB+ to which we added a second log file to cater for growth during an upgrade. This is now no longer needed so we want to remove it. Normally this would be a simple ALTER ...
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1answer
545 views

PostgreSQL WAL Archiving: Does having archive_mode set to 'on' without copying logs cause performance issues?

Using PostgreSQL 8.4/CentOS 6: if I set the archive_mode parameter to on in postgresql.conf, but don't actually store the generated WAL files anywhere via the archive_command parameter, is there any ...
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1answer
213 views

Issue shrinking dev sql server DB's log file

I have a development db that's running on sql 2014 in 2012 compatibility that I'm having an issue with trying to shrink the log file. The mdf is 60+gb and the log is 80+gb but since it's dev like ...
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170 views

Why are we suddenly getting time-outs on multiple transactions? [closed]

Two days ago the transaction log filled up and my user's couldn't update or insert. One of my techs truncated the log, shrank the db, then did a full backup. The next day (Monday) we noticed that ...
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1answer
489 views

SQL Server Troubleshooting Replication and Long-Running fn_dblog query

I am trying to get (pull) Transactional Replication working again for a subscriber. Currently, in Replication Monitor I am seeing messages in the Publisher to Distributor tab and the Distributor to ...
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1answer
174 views

Shrink a large log file for a “Throw Away” database

I have a copy of my prod database on a development server. I am using it to test a deployment script. But when I run it, it says that the log file is full. I checked and it is at 10 GB (Almost the ...
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2answers
65 views

Deleting rows from a table with a very small amount of expansion space

I have multiple tables that I have backed up the data in, and now am deleting the old data for the time, archiving is not an option due to space constraints at this time. I have tried running the ...
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3answers
2k views

ASPState Log file growing tremendously - SQL Server 2008

Microsoft SQL Server 2008 (SP3) - 10.0.5500.0 (X64) Web Edition (64-bit) on Windows NT 6.1 (Build 7601: Service Pack 1) I have an ASPState database online, and its log file ASPState_log is growing ...
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Transaction Log Backups

I am working on backup+recovery scenario and I came across a situation where I could not figure out how I would have to deal with it. We have couple databases where sometimes there may not be any ...
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2answers
161 views

Large number of VLF and shrinking the log

If there are lot number of VLF then it will effect the performance of the queries. I saw that solution is to shrink the log file. But shrinking the file is also bad. So how to take control of whole ...
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3answers
254 views

Transaction Log file .ldf is too small

Current database is almost 200GB however the transaction log file is only 4.1GB. I am worried if this influences the performance of databse and how could it be solved. When I do this query DECLARE ...
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2answers
2k views

SQL Server 2008, switching to simple recovery mode

Currently our transaction log is 50 GB; impressive huh? I want to switch to simple recovery mode and remove the transaction log entirely. Do I need to stop any user activity and detach the database. ...
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2answers
651 views

How to do a one-time log shrink on a database with transactional replication

I have inherited a 10 GB database with an 80 GB log [only 3% in use according to DBCC SQLPERF(logspace)]. It seems safe to assume the extreme log growth was due to problems from long before I was ...
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1answer
100 views

SQL Server - Data and Log Separation

We have a SQL Server 2008 R2 which has, among others, a 12K RPM HDD and a 7.2K RPM HDD. The original intention was to store the data files on the 12K drive and the log files on the 7.2K drive, as is ...
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2answers
1k views

Shrinking a SQL Server Log File Multiple Times

Recently ran into a situation where after a log backup and shrinkfile, the LDF file remained the same size. DBCC LOGINFO clearly showed only one active VLF and SSMS said that 99% of the space in the ...
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1answer
505 views

Maintenance Plan Takes Too Long - Locks Tables - Indexing To Blame

System: I have a Maintenance Plan that Rebuilds Indexes for Several Tables (10 tables, 50M records total). Issue: During the Index Rebuild (~20 minutes), we fail to insert data into the DB ...
2
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2answers
37 views

When is it safe to disable InnoDB doublewrite buffering?

MySQL InnoDB allows us to disable doublewrite buffering by setting innodb_doublewrite = 0. Other databases doesn't seem to allow this setting to be tweaked. How could InnoDB still be able to maintain ...
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2answers
146 views

separating tlog and db file when using fusionio

We have a FusionIO card that we use in our production database. We have both the transaction log as well as the database files on that same drive. I know the recommendation is to place the tlog files ...
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2answers
398 views

How do you fix Autogrowth being set to 12800%

We're running SQLServer 2005 SP1 and for some weird reason our one database transaction log automatically changed it's Autogrowth to 12800% which isn't even a valid number. I cannot change the growth ...
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3answers
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What are the most effective techniques to reduce SQL Server disk space use when updating all rows in a very large table?

Given a SQL Server table with a large number of rows no columns with large-value data types multiple indexes more allocated space than available for the largest possible transaction log size a ...
2
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1answer
141 views

Transaction log autogrowth duration

I am using event notifications to capture data and log file autogrowth events for all databases on my servers. I'm using the data to for analysis of database storage configuration. In looking at the ...
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1answer
2k views

Disable SQL Server Log Shipping to nonexistent destination

I am administering a SQL Server 2008 instance in a dev environment. At some point before I became an administrator, someone enabled log shipping from one of the databases on this dev instance to ...
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1answer
48 views

Is tlog backup on replica clearing VLFs on the primary?

Is it true that a transaction log backup made on the secondary database is clearing the inactive VLFs on the tlog file on the primary database (in case of Availability Groups)? I was not able to find ...
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2answers
90 views

Switching from SIMPLE to FULL recovery mode implications

I have several databases that I'd like to move over to FULL recovery mode so we can have point-in-time restore capability. We don't need it on all of our databases, just the ones that are transaction ...
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2answers
2k views

Transaction log has grown huge after maintenance plan to rebuild idex

A couple of days ago I was testing some stuff using the Maintenance Plans in SQL Server 2008. I created one to rebuild indexes and take a full backup every week. (I know, bad thing I've found out ...