diff --git a/src/assets/styles/messages.css b/src/assets/styles/messages.css
index 39b4f48..f401261 100644
--- a/src/assets/styles/messages.css
+++ b/src/assets/styles/messages.css
@@ -4,3 +4,10 @@
   font-size: 13px;
   padding: 0 24px;
 }
+
+.data-view-warning {
+  height: 40px;
+  line-height: 40px;
+  border-bottom: 1px solid var(--color-border);
+  box-sizing: border-box;
+}
diff --git a/src/assets/styles/typography.css b/src/assets/styles/typography.css
new file mode 100644
index 0000000..a5d334b
--- /dev/null
+++ b/src/assets/styles/typography.css
@@ -0,0 +1,45 @@
+@font-face {
+  font-family: 'Open Sans';
+  src: url('@/assets/fonts/OpenSans-Regular.woff2');
+  font-weight: 400;
+  font-style: normal;
+}
+
+@font-face {
+  font-family: 'Open Sans';
+  src: url('@/assets/fonts/OpenSans-SemiBold.woff2');
+  font-weight: 600;
+  font-style: normal;
+}
+
+@font-face {
+  font-family: 'Open Sans';
+  src: url('@/assets/fonts/OpenSans-Bold.woff2');
+  font-weight: 700;
+  font-style: normal;
+}
+
+@font-face {
+  font-family: 'Open Sans';
+  src: url('@/assets/fonts/OpenSans-Italic.woff2');
+  font-weight: 400;
+  font-style: italic;
+}
+
+@font-face {
+  font-family: 'Open Sans';
+  src: url('@/assets/fonts/OpenSans-SemiBoldItalic.woff2');
+  font-weight: 600;
+  font-style: italic;
+}
+
+@font-face {
+  font-family: 'Open Sans';
+  src: url('@/assets/fonts/OpenSans-BoldItalic.woff2');
+  font-weight: 700;
+  font-style: italic;
+}
+
+a {
+  color: var(--color-accent-shade);
+}
diff --git a/src/components/Graph/AdvancedForceAtlasLayoutSettings.vue b/src/components/Graph/AdvancedForceAtlasLayoutSettings.vue
index 0f2902f..2adc679 100644
--- a/src/components/Graph/AdvancedForceAtlasLayoutSettings.vue
+++ b/src/components/Graph/AdvancedForceAtlasLayoutSettings.vue
@@ -1,5 +1,12 @@
 <template>
-  <Field label="Adjust sizes">
+  <Field label="Scaling ratio">
+    <NumericInput
+      :value="modelValue.scalingRatio"
+      @update="update('scalingRatio', $event)"
+    />
+  </Field>
+
+  <Field label="Prevent overlapping">
     <RadioBlocks
       :options="booleanOptions"
       :activeOption="modelValue.adjustSizes"
@@ -22,13 +29,6 @@
     />
   </Field>
 
-  <Field label="Gravity">
-    <NumericInput
-      :value="modelValue.gravity"
-      @update="update('gravity', $event)"
-    />
-  </Field>
-
   <Field label="Strong gravity mode">
     <RadioBlocks
       :options="booleanOptions"
diff --git a/src/components/Graph/EdgeColorSettings.vue b/src/components/Graph/EdgeColorSettings.vue
index 6798ec0..4016a03 100644
--- a/src/components/Graph/EdgeColorSettings.vue
+++ b/src/components/Graph/EdgeColorSettings.vue
@@ -39,7 +39,10 @@
     </template>
   </Field>
 
-  <Field v-if="modelValue.type !== 'constant'" label="Color as">
+  <Field
+    v-if="modelValue.type !== 'constant' && modelValue.sourceUsage === 'map_to'"
+    label="Color as"
+  >
     <RadioBlocks
       :options="сolorAsOptions"
       :activeOption="modelValue.mode"
@@ -47,7 +50,10 @@
     />
   </Field>
 
-  <Field v-if="modelValue.type !== 'constant'" label="Colorscale direction">
+  <Field
+    v-if="modelValue.type !== 'constant' && modelValue.sourceUsage === 'map_to'"
+    label="Colorscale direction"
+  >
     <RadioBlocks
       :options="сolorscaleDirections"
       :activeOption="modelValue.colorscaleDirection"
diff --git a/src/components/Graph/ForceAtlasLayoutSettings.vue b/src/components/Graph/ForceAtlasLayoutSettings.vue
index 0261543..20fbe8b 100644
--- a/src/components/Graph/ForceAtlasLayoutSettings.vue
+++ b/src/components/Graph/ForceAtlasLayoutSettings.vue
@@ -7,10 +7,10 @@
     />
   </Field>
 
-  <Field label="Scaling ratio">
+  <Field label="Gravity">
     <NumericInput
-      :value="modelValue.scalingRatio"
-      @update="update('scalingRatio', $event)"
+      :value="modelValue.gravity"
+      @update="update('gravity', $event)"
     />
   </Field>
 </template>
diff --git a/src/components/Graph/NodeColorSettings.vue b/src/components/Graph/NodeColorSettings.vue
index e28eb0f..7517532 100644
--- a/src/components/Graph/NodeColorSettings.vue
+++ b/src/components/Graph/NodeColorSettings.vue
@@ -27,7 +27,7 @@
         />
       </Field>
 
-      <Field>
+      <Field v-if="modelValue.type === 'variable'">
         <RadioBlocks
           :options="colorSourceUsageOptions"
           :activeOption="modelValue.sourceUsage"
@@ -45,7 +45,10 @@
     </template>
   </Field>
 
-  <Field v-if="modelValue.type !== 'constant'" label="Color as">
+  <Field
+    v-if="modelValue.type !== 'constant' && modelValue.sourceUsage === 'map_to'"
+    label="Color as"
+  >
     <RadioBlocks
       :options="сolorAsOptions"
       :activeOption="modelValue.mode"
@@ -53,7 +56,10 @@
     />
   </Field>
 
-  <Field v-if="modelValue.type !== 'constant'" label="Colorscale direction">
+  <Field
+    v-if="modelValue.type !== 'constant' && modelValue.sourceUsage === 'map_to'"
+    label="Colorscale direction"
+  >
     <RadioBlocks
       :options="сolorscaleDirections"
       :activeOption="modelValue.colorscaleDirection"
diff --git a/src/lib/graphHelper.js b/src/lib/graphHelper.js
index 6e8303e..5637612 100644
--- a/src/lib/graphHelper.js
+++ b/src/lib/graphHelper.js
@@ -5,8 +5,39 @@ const TYPE_NODE = 0
 const TYPE_EDGE = 1
 const DEFAULT_SCALE = COLOR_PICKER_CONSTANTS.DEFAULT_SCALE
 
+export function dataSourceIsValid(dataSources) {
+  const docColumn = Object.keys(dataSources)[0]
+  if (!docColumn) {
+    return false
+  }
+  try {
+    const records = dataSources[docColumn].slice(0, 10)
+    records.forEach(record => {
+      const parsedRec = JSON.parse(record)
+      if (Object.keys(parsedRec).length < 2) {
+        throw new Error('The records must have at least 2 keys')
+      }
+    })
+    const firstRecord = JSON.parse(records[0])
+    if (
+      !Object.keys(firstRecord).some(key => {
+        return records
+          .map(record => JSON.parse(record)[key])
+          .every(value => value === 0 || value === 1)
+      })
+    ) {
+      throw new Error(
+        'There must be a common key used as object type: 0 - node, 1 - edge'
+      )
+    }
+    return true
+  } catch (err) {
+    return false
+  }
+}
+
 export function buildNodes(graph, dataSources, options) {
-  const docColumn = Object.keys(dataSources)[0] || 'doc'
+  const docColumn = Object.keys(dataSources)[0]
   const { objectType, nodeId } = options.structure
 
   if (objectType && nodeId) {
@@ -110,10 +141,23 @@ function getUpdateSizeMethod(graph, sizeSettings) {
   if (type === 'constant') {
     return attributes => (attributes.size = value)
   } else if (type === 'variable') {
-    return getVariabledSizeMethod(mode, source, scale, min)
+    return attributes => {
+      attributes.size = getVariabledSize(
+        mode,
+        attributes.data[source],
+        scale,
+        min
+      )
+    }
   } else {
-    return (attributes, nodeId) =>
-      (attributes.size = Math.max(graph[method](nodeId) * scale, min))
+    return (attributes, nodeId) => {
+      attributes.size = getVariabledSize(
+        mode,
+        graph[method](nodeId),
+        scale,
+        min
+      )
+    }
   }
 }
 
@@ -184,22 +228,13 @@ function getUpdateEdgeColorMethod(graph, colorSettings) {
   }
 }
 
-function getVariabledSizeMethod(mode, source, scale, min) {
+function getVariabledSize(mode, value, scale, min) {
   if (mode === 'diameter') {
-    return attributes =>
-      (attributes.size = Math.max(
-        (attributes.data[source] / 2) * scale,
-        min / 2
-      ))
+    return Math.max((value / 2) * scale, min / 2)
   } else if (mode === 'area') {
-    return attributes =>
-      (attributes.size = Math.max(
-        Math.sqrt((attributes.data[source] / 2) * scale),
-        min / 2
-      ))
+    return Math.max(Math.sqrt((value / 2) * scale), min / 2)
   } else {
-    return attributes =>
-      (attributes.size = Math.max(attributes.data[source] * scale, min))
+    return Math.max(value * scale, min)
   }
 }
 
diff --git a/src/main.js b/src/main.js
index 2490c54..0aedff8 100644
--- a/src/main.js
+++ b/src/main.js
@@ -5,6 +5,7 @@ import store from '@/store'
 import { createVfm, VueFinalModal, useVfm } from 'vue-final-modal'
 
 import '@/assets/styles/variables.css'
+import '@/assets/styles/typography.css'
 import '@/assets/styles/buttons.css'
 import '@/assets/styles/tables.css'
 import '@/assets/styles/dialogs.css'
diff --git a/src/views/MainView/Workspace/Tabs/Tab/DataView/Chart/index.vue b/src/views/MainView/Workspace/Tabs/Tab/DataView/Chart/index.vue
index 8b5ab87..4d038e4 100644
--- a/src/views/MainView/Workspace/Tabs/Tab/DataView/Chart/index.vue
+++ b/src/views/MainView/Workspace/Tabs/Tab/DataView/Chart/index.vue
@@ -1,6 +1,6 @@
 <template>
   <div ref="chartContainer" class="chart-container">
-    <div v-show="!dataSources" class="warning chart-warning">
+    <div v-show="!dataSources" class="warning data-view-warning">
       There is no data to build a chart. Run your SQL query and make sure the
       result is not empty.
     </div>
@@ -184,13 +184,6 @@ export default {
   height: 100%;
 }
 
-.chart-warning {
-  height: 40px;
-  line-height: 40px;
-  border-bottom: 1px solid var(--color-border);
-  box-sizing: border-box;
-}
-
 .chart {
   min-height: 242px;
 }
diff --git a/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/GraphEditor.vue b/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/GraphEditor.vue
index a566fdf..b792f31 100644
--- a/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/GraphEditor.vue
+++ b/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/GraphEditor.vue
@@ -7,7 +7,9 @@
             <Field>
               Map your result set records to node and edge properties required
               to build a graph. Learn more about result set requirements in the
-              documentation.
+              <a href="https://sqliteviz.com/docs/graph/" target="_blank">
+                documentation</a
+              >.
             </Field>
             <Field label="Object type">
               <Dropdown
@@ -291,7 +293,7 @@ export default {
               nodes: {
                 size: {
                   type: 'constant',
-                  value: 4
+                  value: 10
                 },
                 color: {
                   type: 'constant',
diff --git a/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/index.vue b/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/index.vue
index a372632..7a6e67e 100644
--- a/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/index.vue
+++ b/src/views/MainView/Workspace/Tabs/Tab/DataView/Graph/index.vue
@@ -1,13 +1,20 @@
 <template>
   <div ref="graphContainer" class="graph-container">
-    <div v-show="!dataSources" class="warning chart-warning">
+    <div v-show="!dataSources" class="warning data-view-warning">
       There is no data to build a graph. Run your SQL query and make sure the
       result is not empty.
     </div>
+    <div v-show="!dataSourceIsValid" class="warning data-view-warning">
+      Result set is invalid for graph visualisation. Learn more in
+      <a href="https://sqliteviz.com/docs/graph/" target="_blank">
+        documentation</a
+      >.
+    </div>
     <div
       class="graph"
       :style="{
-        height: !dataSources ? 'calc(100% - 40px)' : '100%'
+        height:
+          !dataSources || !dataSourceIsValid ? 'calc(100% - 40px)' : '100%'
       }"
     >
       <GraphEditor
@@ -25,6 +32,7 @@
 import 'react-chart-editor/lib/react-chart-editor.css'
 import events from '@/lib/utils/events'
 import GraphEditor from './GraphEditor.vue'
+import { dataSourceIsValid } from '@/lib/graphHelper'
 
 export default {
   name: 'Graph',
@@ -48,7 +56,6 @@ export default {
       resizeObserver: null
     }
   },
-
   created() {
     this.$emit('update:exportToSvgEnabled', false)
     this.$emit('update:exportToHtmlEnabled', false)
@@ -66,6 +73,11 @@ export default {
       this.handleResize()
     }
   },
+  computed: {
+    dataSourceIsValid() {
+      return !this.dataSources || dataSourceIsValid(this.dataSources)
+    }
+  },
   methods: {
     getOptionsForSave() {
       return this.$refs.graphEditor.settings
@@ -93,13 +105,6 @@ export default {
   height: 100%;
 }
 
-.chart-warning {
-  height: 40px;
-  line-height: 40px;
-  border-bottom: 1px solid var(--color-border);
-  box-sizing: border-box;
-}
-
 .graph {
   min-height: 242px;
 }
diff --git a/src/views/MainView/Workspace/Tabs/Tab/DataView/Pivot/index.vue b/src/views/MainView/Workspace/Tabs/Tab/DataView/Pivot/index.vue
index 3b7a54c..fd3dbbb 100644
--- a/src/views/MainView/Workspace/Tabs/Tab/DataView/Pivot/index.vue
+++ b/src/views/MainView/Workspace/Tabs/Tab/DataView/Pivot/index.vue
@@ -326,4 +326,8 @@ export default {
 .pivot-output:empty {
   flex-grow: 0;
 }
+
+:deep(.js-plotly-plot) {
+  height: 100%;
+}
 </style>
diff --git a/src/views/MainView/Workspace/index.vue b/src/views/MainView/Workspace/index.vue
index 0c284e5..36c9344 100644
--- a/src/views/MainView/Workspace/index.vue
+++ b/src/views/MainView/Workspace/index.vue
@@ -42,8 +42,8 @@ export default {
     ) {
       const stmt = [
         '/*',
-        ' * Your database is empty. In order to start building charts',
-        ' * you should create a table and insert data into it.',
+        ' * Your database is empty. In order to start building data visualisations',
+        ' * you should create tables and insert data into them.',
         ' */',
         'CREATE TABLE house',
         '(',
@@ -54,7 +54,20 @@ export default {
         "('Gryffindor', 100),",
         "('Hufflepuff', 90),",
         "('Ravenclaw', 95),",
-        "('Slytherin', 80);"
+        "('Slytherin', 80);",
+        '',
+        'CREATE TABLE student',
+        '(',
+        '  id INTEGER,',
+        '  name TEXT,',
+        '  house TEXT',
+        ');',
+        'INSERT INTO student VALUES',
+        "(1, 'Harry Potter', 'Gryffindor'),",
+        "(2, 'Ron Weasley', 'Gryffindor'),",
+        "(3, 'Draco Malfoy', 'Slytherin'),",
+        "(4, 'Luna Lovegood', 'Ravenclaw'),",
+        "(5, 'Cedric Diggory', 'Hufflepuff');"
       ].join('\n')
 
       const tabId = await this.$store.dispatch('addTab', { query: stmt })