1. very large Databases
in your future
Eric Peterson

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

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

4. impact? Everything takes longer ! Example db raw disk I/O SQLIO
raw network
2.2 TB = 2,222 GB
sqliosim | iometer
I/O 397 MB/sec = 23 GB/min
10gb/sec = 1.25 GB/sec = 75 GB/min

5. impact?

6. impact? backup / restore copies & initial sync re-index
19 GB/min or 2,222 GB in 108 min
75 GB/min or 2,222 GB in 30 min
11 GB/min or 2,222 GB in 300 min

7. I/O data transfers backup 19 GB/min hh:mm GB 00:05 100 00:49 1000
01:48
2222
08:06
10,000

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

9. I/O data transfers reindex 11 GB/min hh:mm GB 00:14 100 02:15 1,000
05:00
2,222
2230
10,000

10. impact? maintenance window query optimizer; 200 step histogram
test environment
large logs
TempDB
temp tables, sorts, joins, online indexing, snapshot isolation

11. why? queries & rollbacks network copies backups synchronization
one table 266m rows
222GB data, 285GB index
20 sec table scan
graphic of disk, memory & network

12. 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

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

14. Other fixes partitioning Enterprise Edition per table
needs useful primary key
sliding window automation
reference to codeplex.com partitioning

15. other fixes

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

17. other fixes
multiple data files

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

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

20. Operations monitoring sp_whoisactive sys.dm_exec_procecure_stats
history
output from whoisactive and sys.dm…

21. Operations monitoring (with history) sp_whoisactive
sys.dm_exec_procedure_stats
history
output from whoisactive and sys.dm…

22. operations
look for anomalies
can change query plan

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

24. operations
query tuning
large table scans
large joins
excessive reads

25. Operations
work in batches

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

27. thanks!
contact info
Eric Peterson

28. Thank you to all of our Sponsors!
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9/19/2015
SQLSaturday #441 – Denver 2015

29. Thank you to all of our Sponsors!
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9/19/2514
SQLSaturday #441 – Denver 2015