## Answer SQL Server Express is a free edition of SQL Server. There are no functional restrictions for using Pleasanter, but there are limitations on available resource limits. --- ## Overview SQL Server Express has the following restrictions. In particular, if database usage exceeds the limits below, errors will occur when writing data, and the login screen may not be displayed. Additionally, due to memory and CPU limits, expected performance may not be achieved even if the server has high specifications. ### Resources Even if the server where SQL Server Express is installed has high specifications, it cannot use resources exceeding the following limits. |Resource|Limit| |---|---| |Database capacity|SQL Server 2025 Express and later: 50 GB<br>SQL Server 2022 Express and earlier: 10 GB| |Memory capacity|1410MB| |CPU|1 physical CPU or 4 cores, whichever is smaller| ### Maintenance Plans [Schedule and automate backups of SQL Server databases in SQL Server Express](https://learn.microsoft.com/en-us/troubleshoot/sql/database-engine/backup-restore/schedule-automate-backup-database), so "regular database backups" using maintenance plans are not available. When performing regular backups with SQL Server Express, please refer to the following page. [Back Up The Database (SQL Server) in Pleasanter](backup-sql-server) ### Detailed Information For other details, please refer to the following official Microsoft pages: [Editions and supported features of SQL Server 2025 - SQL Server | Microsoft Learn](https://learn.microsoft.com/en-us/sql/sql-server/editions-and-components-of-sql-server-2025) [Editions and supported features of SQL Server 2022 - SQL Server | Microsoft Learn](https://learn.microsoft.com/en-us/sql/sql-server/editions-and-components-of-sql-server-2022?view=sql-server-ver16) [Editions and supported features of SQL Server 2019 - SQL Server | Microsoft Learn](https://learn.microsoft.com/en-us/sql/sql-server/editions-and-components-of-sql-server-2019?view=sql-server-ver15) [Editions and supported features of SQL Server 2017 - SQL Server | Microsoft Learn](https://learn.microsoft.com/en-us/sql/sql-server/editions-and-components-of-sql-server-2017)