Tables in SharePoint Content Database

Below are some of the basic tables within a content database and a very high level diagram on some of the relationships between them

Features	Table that holds information about all the activated features for each site collection or site.
Sites	Table that holds information about all the site collections for this content database.
Webs	Table that holds information about all the specific sites (webs) in each site collection.
UserInfo	Table that holds information about all the users for each site collection.
Groups	Table that holds information about all the SharePoint groups in each site collection.
Roles	Table that holds information about all the SharePoint roles (permission levels) for each site.
All Lists	Table that holds information about lists for each site.
GroupMembership	Table that holds information about all the SharePoint group members.
AllUserData	Table that holds information about all the list items for each list.
AllDocs	Table that holds information about all the documents (and all list items) for each document library and list.
RoleAssignment	Table that holds information about all the users or SharePoint groups that are assigned to roles.
Sched Subscriptions	Table that holds information about all the scheduled subscriptions (alerts) for each user.
ImmedSubscriptions	Table that holds information about all the immediate subscriptions (alerts) for each user.

If SharePoint Log is growing large – Things to consider :

If you are going to stick with Full Recovery, make sure you're doing *Transaction Log* backups, this is what empties the TLog.

Also, do not run Update Statistics or Reindex jobs from SQL Maintenance Plans against SharePoint databases. SharePoint has specific Health Analyzer rules (timer jobs) that do this activity for you.

If you're in Simple recovery mode then the log files should automatically empty whenever SQL thinks it's come to a sensible stopping point. If you're in Full recovery mode then the log files will continue to grow until a Full backup is taken. A second backup will then empty the logs out.

If you need to be in the full recovery model then run two full backups. The log files will probably not reduce in size immediately and a shrink may be required. You will then need to schedule a backup schedule to prevent the log files re-growing on you.

It is better to check backup logs regulary and it is needed to run a manual backup if it fails.

SharePoint ULS Logging PowerShell Commands

1.    In order to merge all the log files from all servers in a farm for particular time period, need to use below command
Merge-SPLogFile -StartTime '03/15/2016 00:00' -EndTime '03/16/2016 00:00' -Path c:\temp\upgrade.log -Overwrite

2.    If you want to create new log file then enter below command
New-SPLogFile

3.    If you want to enable verbose logging then enter below command
Set-LogLevel -TraceSeverity Verbose -EventSeverity Verbose


4.    If you want to merge all the log files in farm from different servers by using co relation id, then use below command
Merge-SPLogFile -Path C:\Logfile.log -Correlation <<Co Relation ID>>

5.    If you want to set to default values of logging then use the below command
Clear-SPLogLevel