Reporting on History tables.Summary<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: ; width: auto; height: auto; } } The purpose of this article is to explain why History tables should not be used for reporting.Using the sys_history_line and sys_history_set tables without understanding how they work can lead to significant issues with data visibility across multiple areas, including reports, dashboards, and other analytics. The [sys_history_set] and [sys_history_line] tables are part of the History Sets plugin (com.glide.history_set). Their purpose is to display a record’s history in table format by pulling information from various sources such as sys_audit, sys_email, and sys_relationship (see History Sets for more details). A sys_history_set record contains a collection of related sys_history_line records. These records are generated dynamically when accessed and are automatically removed by the table cleaner 28 days after their most recent use. Because the history data is deleted if a record (such as an Incident, Problem, or Change) has not been accessed in the past 28 days, reporting on these tables will not provide accurate or complete information. Related Links<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: ; width: auto; height: auto; } } KB0547662 - Auditing and history sets | How they work together KB0744473 - History sets - How are they generated