1. Very Large Databases in your future
Eric Peterson
4/2/2016

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3. VLDB how large? impact? why? easy fixes other fixes maintenance
operations

4. how large? terabyte + depends on hardware my examples
2.2 TB (2,222 GB) db
2 - 4 gb HBA
10 gb network
EMC VNX 5500 SAN
tiered storage

5. impact? everything takes more time ! example db raw disk I/O
SQLIOSIM, SQLIO, IoMeter, others
raw network
times based on 7 day average
2.2 TB = 2,222 GB
I/O 397 MB/sec = 23 GB/min
sqliosim | iometer
10gb/sec = 1.25 GB/sec = 75 GB/min

6. impact?

7. impact? backup / restore copies & initial sync re-index
19 GB/min or 2.2 TB in 108 min
75 GB/min or 2.2 TB in 30 min
11 GB/min or 2.2 TB in 300 min

8. I/O data transfers backup 19 GB/min GB hh:mm 100 00:05 1,000 00:49
2,222
01:08
10,000
08:06

9. I/O data transfers copy 75 GB/min GB hh:mm 100 00:01 1,000 00:13 2,222
00:30
10,000
02:13

10. I/O data transfers reindex 11 GB/min GB hh:mm 100 00:14 1,000 02:15
2,222
05:00
10,000
22:30

11. impact? maintenance window query optimizer; 200 step histogram
other environments
dev qa

12. impact? large logs TempDB temp tables sorts joins online indexing
snapshot isolation

13. why? queries scans are deadly rollbacks one table 266m rows
222GB data, 285GB index
20 sec table scan
graphic of disk, memory & network

14. why? network copies backups synchronization
graphic of disk, memory & network

15. Easy fixes compress data Enterprise Edition less I/O, more CPU
per table / index
sp_estimate_data_compression_savings
no LOB
compression estimator sql
slavasql.blogspot.co.uk/2014/08/sql-server-data-compression-hidden-gem.html

16. easy fixes archive / purge data old / unnecessary data
multiple TempDB files
upgrade system / hardware
add RAM
faster disks

17. Other fixes partitioning Enterprise Edition per table
needs useful primary key
sliding window automation (CodePlex)
reference to codeplex.com partitioning

18. other fixes

19. other fixes multiple data files concurrent reads/writes
requires file groups
maintenance window to move data
columnstore (in-memory) indexes
be aware of restrictions

20. Maintenance online index rebuild Enterprise Edition duplicate space
no XML, spatial, columnstore
single partition reindex
Paul Randall DBCC with VLDB article

21. Maintenance DBCC run on copy CheckAlloc, CheckCatalog, CheckTable
Paul Randall DBCC VLDB article
filegroups
manually grow equal size files

22. Operations monitoring sp_whoisactive sys.dm_exec_procedure_stats
need history
output from whoisactive and sys.dm…

23. Operations monitoring sp_whoisactive sys.dm_exec_procedure_stats
need history
output from whoisactive and sys.dm…

24. operations
look for anomalies
can change query plan

25. operations query tuning scans of large tables joins to large tables
excessive reads

26. operations query tuning scans of large tables joins to large tables
excessive reads

27. Operations
work in batches

28. Operations snapshot isolation Change Data Capture
new data to warehouse
NOLOCK ?
parallelism
cost threshold

29. thanks!
contact info
Eric Peterson