WRITELOG waits happen while SQL Server waits for a log flush to finish, usually in busy transactional databases. What causes them and how to reduce them.
SQL SERVER – Guest Post – Jonathan Kehayias – Wait Type – Day 16 of 28
Jonathan Kehayias, an MCITP with a passion for performance tuning, writes a guest post for Day 16 of my wait types series, and I share why I admire him.
SQL SERVER – LCK_M_XXX – Wait Type – Day 15 of 28
LCK_M_XXX wait types show tasks waiting to acquire a lock, such as LCK_M_S or LCK_M_IX. Day 15 explains locking and what these lock waits mean.
SQL SERVER – BACKUPIO, BACKUPBUFFER – Wait Type – Day 14 of 28
BACKUPIO and BACKUPBUFFER waits happen when a backup task waits for data or a buffer. Day 14 shares a real client case and the workaround I used.
SQL SERVER – FT_IFTS_SCHEDULER_IDLE_WAIT – Full Text – Wait Type – Day 13 of 28
FT_IFTS_SCHEDULER_IDLE_WAIT is a background full text wait type that does not matter and should be filtered out. Day 13 also lists other FT_ waits.
SQL SERVER – PAGELATCH_DT, PAGELATCH_EX, PAGELATCH_KP, PAGELATCH_SH, PAGELATCH_UP – Wait Type – Day 12 of 28
PAGELATCH_EX and PAGEIOLATCH_EX are not the same. Day 12 explains latches and why PAGELATCH waits are not about IO but often linked to a buffer issue.
SQL SERVER – ASYNC_IO_COMPLETION – Wait Type – Day 11 of 28
ASYNC_IO_COMPLETION shows up when tasks wait for I/O, often during BACKUP, CREATE DATABASE or ALTER DATABASE. Day 11 covers what to check.