# How to diagnose and fix a slow Infor LN session > Source: https://netray.co/erp-help/ln-performance-tuning-slow-sessions > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: ERP Help ## Short answer A slow Infor LN session is usually caused by an unindexed or overly broad database query, unarchived data bloating a transaction table, or resource pressure on the Java application tier, and occasionally by a recently added custom DAL2 handler. The fix starts with isolating which tier the delay is actually in rather than guessing at a solution. ## Kind advanced ## System infor-ln ## Erp Infor LN ## Module Performance / System Administration ## Query infor ln session running slow how to fix ## Alternate Queries - infor ln performance tuning guide - infor ln slow query troubleshooting - why is infor ln so slow - optimize infor ln database performance ## Applies To Infor LN Enterprise Edition, all supported databases (SQL Server, Oracle) ## Steps ### Diagnose and fix a slow Infor LN session **Items:** - Reproduce the slowness and note exactly which action is slow: opening the session, applying a filter, saving a record, or running a report from it. - Check whether the slowdown is specific to one company or VRC or affects the whole environment, which points toward data volume versus infrastructure. - Capture the underlying SQL for the slow action and check its execution plan for missing indexes or table scans. - Review row counts and index maintenance, statistics and fragmentation, on the tables the session queries, especially high-volume transaction tables. - Check application server resource usage, CPU, memory and garbage collection pauses, on the Java-based Enterprise Edition runtime during the slow period. - Review any custom DAL2 handlers or classic DAL logic on the affected table that could be adding overhead on every read or write. - Check network latency between client, application server and database, particularly for remote or VPN-connected users. - Apply the fix that matches the bottleneck: add or rebuild an index, archive old data, tune JVM memory and GC settings, or optimize the custom logic. - Re-test the same action and record the before and after timing so the fix is documented and measurable. ## Sections ### Database-tier causes **Body:** The most common root cause is a session's filter or overview query running against a large table without a supporting index, or a query with a broad date range or wildcard that forces a scan instead of a seek. Also check for outdated statistics after a bulk load or conversion, and index fragmentation on tables that see heavy update activity, such as inventory or order lines, since both quietly degrade a query plan that used to be fine. ### Application-tier causes **Body:** Because Enterprise Edition LN runs on a Java application server, garbage collection pauses, an undersized JVM heap, or too few worker threads under peak load tend to show up as generalized slowness across many sessions rather than one specific query. If several unrelated sessions all degrade around the same time of day, check server-side monitoring for the application tier before assuming it is a data problem in any one table. ### Data volume and archiving **Body:** Environments that never archive completed orders, closed work orders or old transactional history grow tables far beyond what indexing alone can compensate for. Overview queries, MRP runs and reports all scan a larger dataset than necessary when closed and historical records stay mixed in with live data. Archiving closed and old records out of the live path, using Infor's archiving tooling or a documented custom process, often helps more than any single index change, particularly on environments that have been live for many years. ### Custom code as a hidden cause **Body:** A DAL2 handler or classic DAL customization that performs even a small extra lookup on every save multiplies across thousands of transactions a day. When a specific session degrades right after a release, review recently added or changed customizations on that table first, before assuming the cause is purely database-side. ## Pitfalls - Adding an index without checking its impact on write performance for a heavily inserted table. - Blaming the network or the client PC before checking the actual SQL execution plan. - Tuning JVM memory settings without a baseline measurement, making it hard to prove the change actually helped. - Ignoring statistics and index maintenance jobs, so a fix applied months ago silently stops working as data keeps growing. - Treating every slow session as a database problem when a recently deployed DAL2 handler is the real cause. - Not isolating whether the issue affects one company or VRC versus the whole environment before starting to tune. ## Ai Angle When a user reports a specific session as slow, a grounded AI agent can correlate the session and table involved with recent customization changes and known large tables in that environment, narrowing the likely cause before a DBA even opens a query monitor, which cuts down a lot of the back-and-forth in early diagnosis. ## Faq ### Is Infor LN performance mostly a database problem? **Answer:** Often, but not always. Database-tier issues such as missing indexes, stale statistics or unarchived data are the most common cause, but the Java application server tier and custom DAL2 or DAL logic can also be the bottleneck, so confirm where the time is actually going before tuning. ### Does archiving old data really help LN performance? **Answer:** Yes, meaningfully, for environments running for years without archiving. Overview queries, MRP runs and reports all scan larger tables than necessary when closed orders and old transactions are never moved out of the live dataset. ### How do I know if a slow session is caused by a customization? **Answer:** Compare when the slowness started against your customization or patch history. If a DAL2 handler or DAL script was added or changed on that table around the same time, test with it temporarily disabled in a non-production environment to confirm. ### Can JVM tuning fix one slow session by itself? **Answer:** Rarely on its own. JVM and application server tuning generally improves overall throughput and reduces generalized slowness under load, but a single session that is slow in isolation is more often a query or indexing problem specific to that session's tables. ## Search terms infor ln performance tuning, infor ln slow session fix, infor ln database indexing, infor ln query performance, infor ln jvm tuning, infor ln data archiving, infor ln enterprise edition slow, optimize infor ln sql server, infor ln dal2 performance, baan ln performance troubleshooting --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json