Database-backed web applications are prone to performance bugs related to database accesses. While much work has been conducted on database-access antipatterns with some recent work focusing on performance impact, there still lacks a comprehensive view of database-access performance antipatterns in database-backed web applications. To address this issue, we first summarize and report all known database-access performance antipatterns found through our literature survey. We further look at web applications that access databases through language-provided SQL interfaces, which have been largely ignored by recent work, to extract new antipatterns based on real-world performance bugs from such web applications. We also evaluate the effectiveness of rule-based antipattern detection on such web applications. Our study in total reports 24 known and 10 new database-access performance antipatterns. Our results can guide future work to develop effective tool support for different types of web applications.