The following issues were fixed in Graph Visualiser:

1) Allow the user to set the row limit and chart line width.
2) Zoom should only be applied to X-axis, not both.
3) On clicking the 'Generate' button, the chart should return to its original zoom level.
4) Negative values are not displayed.

refs #7485

web/pgadmin/tools/sqleditor/__init__.py

@@ -1089,11 +1089,11 @@ def fetch(trans_id, fetch_all=None):
 
 
 @blueprint.route(
-    '/fetch_all_from_start/<int:trans_id>', methods=["GET"],
+    '/fetch_all_from_start/<int:trans_id>/<int:limit>', methods=["GET"],
     endpoint='fetch_all_from_start'
 )
 @login_required
-def fetch_all_from_start(trans_id):
+def fetch_all_from_start(trans_id, limit=-1):
     """
     This function is used to fetch all the records from start and reset
     the cursor back to it's previous position.
@@ -1111,7 +1111,7 @@ def fetch_all_from_start(trans_id):
         # Reset the cursor to start to fetch all the records.
         conn.reset_cursor_at(0)
 
-        status, result = conn.async_fetchmany_2darray(-1)
+        status, result = conn.async_fetchmany_2darray(limit)
         if not status:
             status = 'Error'
         else:

web/pgadmin/tools/sqleditor/static/js/components/sections/GraphVisualiser.jsx

@@ -69,6 +69,7 @@ function GenerateGraph({graphType, graphData, ...props}) {
   let showDataPoints = queryToolCtx.preferences.graphs['graph_data_points'];
   let useDiffPointStyle = queryToolCtx.preferences.graphs['use_diff_point_style'];
   let showToolTip = queryToolCtx.preferences.graphs['graph_mouse_track'];
+  let lineBorderWidth = queryToolCtx.preferences.graphs['graph_line_border_width'];
 
   // Below options are used by chartjs while rendering the graph
   const options = useMemo(()=>({
@@ -76,6 +77,9 @@ function GenerateGraph({graphType, graphData, ...props}) {
       point: {
         radius: showDataPoints ? DATA_POINT_SIZE : 0,
       },
+      line: {
+        borderWidth: lineBorderWidth,
+      },
     },
     plugins: {
       legend: {
@@ -100,7 +104,7 @@ function GenerateGraph({graphType, graphData, ...props}) {
             borderWidth: 1,
             backgroundColor: 'rgba(54, 162, 235, 0.3)'
           },
-          mode: 'xy',
+          mode: 'x',
         },
       }
     },
@@ -249,12 +253,16 @@ export function GraphVisualiser({initColumns}) {
   const onGenerate = async ()=>{
     setLoaderText(gettext('Fetching all the records...'));
 
+    onResetZoom();
+
     let url = url_for('sqleditor.fetch_all_from_start', {
-      'trans_id': queryToolCtx.params.trans_id
+      'trans_id': queryToolCtx.params.trans_id,
+      'limit': queryToolCtx.preferences.sqleditor.row_limit
     });
 
     let res = await queryToolCtx.api.get(url);
 
+    setLoaderText(gettext('Rendering data points...'));
     // Set the Graph Data
     setGraphData(
       getGraphDataSet(res.data.data.result, columns, xaxis, yaxis, queryToolCtx)
@@ -265,7 +273,7 @@ export function GraphVisualiser({initColumns}) {
 
   // Reset the zoom to normal
   const onResetZoom = ()=> {
-    chartObjRef.current.resetZoom();
+    chartObjRef?.current?.resetZoom();
   };
 
   // Download button callback

web/pgadmin/tools/sqleditor/utils/query_tool_preferences.py

@@ -12,7 +12,7 @@ from flask_babel import gettext
 from pgadmin.utils.constants import PREF_LABEL_DISPLAY,\
     PREF_LABEL_KEYBOARD_SHORTCUTS, PREF_LABEL_EXPLAIN, PREF_LABEL_OPTIONS,\
     PREF_LABEL_EDITOR, PREF_LABEL_CSV_TXT, PREF_LABEL_RESULTS_GRID,\
-    PREF_LABEL_SQL_FORMATTING
+    PREF_LABEL_SQL_FORMATTING, PREF_LABEL_GRAPH_VISUALISER
 from pgadmin.utils import SHORTCUT_FIELDS as shortcut_fields, \
     ACCESSKEY_FIELDS as accesskey_fields
 
@@ -806,3 +806,13 @@ def register_query_tool_preferences(self):
             'when the tab key or auto-indent are used.'
         )
     )
+
+    self.row_limit = self.preference.register(
+        'graph_visualiser', 'row_limit',
+        gettext("Row Limit"), 'integer',
+        10000, min_val=1, category_label=PREF_LABEL_GRAPH_VISUALISER,
+        help_str=gettext('This setting specifies the maximum number of rows '
+                         'that will be plotted on a chart. Increasing this '
+                         'limit may impact performance if charts are plotted '
+                         'with very high numbers of rows.')
+    )