How are logical reads different from lob reads?
Scan count 1, logical reads 3, physical reads 1, read-ahead reads 0, lob logical reads 300, lob physical reads 37, lob read-ahead reads 400. Why are the LOB reads so different?
What are the execution times for logical reads?
Scan count 1, logical reads 148, physical reads 0, read-ahead reads 148, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. SQL Server Execution Times: CPU time = 31 ms, elapsed time = 297 ms. (19972 row (s) affected) Table ‘Person’.
What are the number of logical reads in SQL Server?
Scan count 1, logical reads 148, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. SQL Server Execution Times: CPU time = 16 ms, elapsed time = 186ms. The Output Message above shows different number of Reads for both the queries when ran twice.
Why are there no lob reads in Excel?
The LOB data itself is never accessed (zero LOB reads), because the variable is never read. Even if it were, it would only be via the LOB handle last assigned. There are no LOB reads because the LOB data is never accessed. This plan uses the bulk rowset provider to copy the LOB data from the source table to the new table.
Why does SQL Server read different LOB data?
1 Answer 1. Not all reads are equal. SQL Server knows that accessing LOB data is expensive, and tries to avoid it when possible. There are also detailed differences in the way the LOB data is read in each case: Summary. The numbers are different because: Detail. The Clustered Index Scan does not read any LOB data.
Which is the best buffer cache for lobs?
CACHE is the best option for LOBs requiring a lot of read/write activity. CACHE READS helps when you create the LOB once and read data from it and the size of LOBs to be read in the system at any time does not take too much space out of the buffer pool. “Write” processes are implemented in the same way as in the NOCACHE option.