doc: replace connexion pool size by database connexion to avoid confusion (#2251)

README.md

@@ -103,7 +103,7 @@ The customer's environment imposed a high cost of new connection acquisition, an
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 #### You're [probably] doing it wrong
 <a href="https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing"><img width="200" align="right" src="https://github.com/brettwooldridge/HikariCP/wiki/Postgres_Chart.png"></a>
-AKA *"What you probably didn't know about connection pool sizing"*.  Watch a video from the Oracle Real-world Performance group, and learn about why connection pools do not need to be sized as large as they often are.  In fact, oversized connection pools have a clear and demonstrable *negative* impact on performance; a 50x difference in the case of the Oracle demonstration.  [Read on to find out](https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing).
+AKA *"What you probably didn't know about connection pool sizing"*.  Watch a video from the Oracle Real-world Performance group, and learn about why database connections do not need to be so numerous as they often are. In fact, too many connections have a clear and demonstrable *negative* impact on performance; a 50x difference in the case of the Oracle demonstration.  [Read on to find out](https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing).
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 #### WIX Engineering Analysis
 <a href="https://www.wix.engineering/blog/how-does-hikaricp-compare-to-other-connection-pools"><img width="180" align="left" src="https://github.com/brettwooldridge/HikariCP/wiki/Wix-Engineering.png"></a>