… in my presentation that sometimes these perform worse and sometimes better than another equivalent solution. If you’re talking about using a… is known to have poor performance, but it returns a better random choice. Another workaround may be to add a column… the result was that it created a temporary table to count the movies per production year for each kind_id. It…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… 3x better. The interesting item here is that vCache with time-based flushing enabled actually produces better and more consistent performance than vCache… –num-threads=32 –test=tests/db/oltp.lua –oltp_tables_count=32 \ –oltp-table-size=10000000 –rand-init=on –report-interval…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…the strong side of TokuDB: it has more than 4x data compression on this dataset. We can…15GB and 232.927.460 records So TokuDB looks better in this workload, however the sparse throughput is… back_log = 50 max_connections = 2000 max_prepared_stmt_count=500000 max_connect_errors = 10 table_open_cache =…
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…-stdin –dispatcher-plugin thread-pool –thread-pool-threads-count 100 –session-init-query \”set innodb_fake_changes=1\”…features to Percona Playback to make it work better for this use case. You will need …that have duplicate key errors may be faster than an actual database write. The slow logs …
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 18 Comments
… made to MySQL so that is could better utilize all available resources (that is, scale better) when running small numbers of queries… of collected flight data. For example (the final query): select count(*) from ontime.ontime where FlightDate BETWEEN ’1988-01-01′ and…, even with a single server Shard-Query will perform much better than regular MySQL as the volume of data grows. Remember that…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
… table: mysql> select count(*), count(distinct UniqueCarrier) from dim_flightG *************************** 1. row *************************** count(*): 58625 count(distinct UniqueCarrier): 29…scale up configuration it does not perform any better than the baseline, and actually performed just a little…
Post: Air traffic queries in InfiniDB: early alpha
November 2, 2009 By 19 Comments
… also explains what takes so much space. Queries First count start query SELECT count(*) FROM ontime took 2.67 sec, which shows… is summary table with queries times (in sec, less is better) QueryMonetDBInfoBrightLucidDBInfiniDB Q029.94.19103.21NA Q17.912.1349.176.79… really good time for queries it can handle, quite often better than InfoBright. Inability to handle derived tables is significant drawback for…
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
… be fixed before release. MyISAM shows stable result. InnoDB is better than MyISAM by 58% in case with 4 threads, but does… is better than MyISAM by 2-26 times and than Falcon by 1.64 – 3.85 times. READ_PK_RANGE_INDEX Query: SELECT count… is better than MyISAM by ~30% with 4-16 threads, but MyISAM scales a bit better in this case. InnoDB is better than Falcon by…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
… queries and explain the results so that you have a better understanding of when using the Hash Join will be best… 5.5 is as follows: SELECT s_nationkey, l_shipmode, count(*) FROM supplier INNER JOIN lineitem ON s_suppkey = l_suppkey… becomes costly in comparison. Block Nested Loop Join would perform better than Hash Join when you are joining two tables on a…
Comment: A common problem when optimizing COUNT()
September 22, 2008 By 19 Comments
…? To address the off-topic 
The hope that COUNT(col1) is faster than COUNT(*) is false indeed. Take a look at this: create… as COUNT(*), if not better,” what metric of goodness are you using? In performance it can never be better; in optimizability/understandability/maintainability, COUNT…
