|
| 1 | +/** |
| 2 | + * Indexed Field Query Optimization |
| 3 | + * |
| 4 | + * This snippet demonstrates how to leverage database indexes for optimal query performance |
| 5 | + * in ServiceNow GlideRecord operations. |
| 6 | + * |
| 7 | + * Use Case: High-performance queries on large tables |
| 8 | + * Performance Benefits: Faster query execution, reduced database load |
| 9 | + * |
| 10 | + * @author ServiceNow Community |
| 11 | + * @version 1.0 |
| 12 | + */ |
| 13 | + |
| 14 | +// Method 1: Using Indexed Fields for Optimal Performance |
| 15 | +function queryWithIndexedFields() { |
| 16 | + var gr = new GlideRecord('incident'); |
| 17 | + |
| 18 | + // GOOD: Query on indexed fields (state, priority, assignment_group are typically indexed) |
| 19 | + gr.addQuery('state', 'IN', '2,3'); // Work in Progress, On Hold |
| 20 | + gr.addQuery('priority', '<=', '3'); // High priority and above |
| 21 | + gr.addQuery('assignment_group', '!=', ''); // Has assignment group |
| 22 | + |
| 23 | + // GOOD: Use sys_created_on for date ranges (indexed timestamp) |
| 24 | + gr.addQuery('sys_created_on', '>=', gs.daysAgoStart(7)); |
| 25 | + gr.addQuery('sys_created_on', '<=', gs.daysAgoEnd(1)); |
| 26 | + |
| 27 | + // GOOD: Order by indexed field |
| 28 | + gr.orderBy('sys_created_on'); |
| 29 | + |
| 30 | + gr.query(); |
| 31 | + |
| 32 | + var results = []; |
| 33 | + while (gr.next()) { |
| 34 | + results.push({ |
| 35 | + number: gr.getDisplayValue('number'), |
| 36 | + state: gr.getDisplayValue('state'), |
| 37 | + priority: gr.getDisplayValue('priority') |
| 38 | + }); |
| 39 | + } |
| 40 | + |
| 41 | + return results; |
| 42 | +} |
| 43 | + |
| 44 | +// Method 2: Avoiding Non-Indexed Field Queries |
| 45 | +function avoidNonIndexedQueries() { |
| 46 | + // BAD EXAMPLE - Don't do this on large tables |
| 47 | + function badQueryExample() { |
| 48 | + var gr = new GlideRecord('incident'); |
| 49 | + |
| 50 | + // BAD: Contains query on non-indexed text field |
| 51 | + gr.addQuery('description', 'CONTAINS', 'network issue'); |
| 52 | + |
| 53 | + // BAD: Complex wildcard search |
| 54 | + gr.addQuery('short_description', 'STARTSWITH', 'Unable'); |
| 55 | + |
| 56 | + gr.query(); |
| 57 | + return gr.getRowCount(); // Also bad on large tables |
| 58 | + } |
| 59 | + |
| 60 | + // GOOD ALTERNATIVE - Use indexed fields and full-text search |
| 61 | + function goodQueryAlternative() { |
| 62 | + var gr = new GlideRecord('incident'); |
| 63 | + |
| 64 | + // GOOD: Use category/subcategory (often indexed) |
| 65 | + gr.addQuery('category', 'network'); |
| 66 | + |
| 67 | + // GOOD: Use indexed fields first to narrow results |
| 68 | + gr.addQuery('state', 'IN', '1,2,3'); |
| 69 | + gr.addQuery('sys_created_on', '>=', gs.daysAgoStart(30)); |
| 70 | + |
| 71 | + // Then filter on text if needed (smaller result set) |
| 72 | + gr.addQuery('short_description', 'CONTAINS', 'unable'); |
| 73 | + |
| 74 | + gr.query(); |
| 75 | + |
| 76 | + var results = []; |
| 77 | + while (gr.next()) { |
| 78 | + results.push(gr.getUniqueValue()); |
| 79 | + } |
| 80 | + |
| 81 | + return results; |
| 82 | + } |
| 83 | + |
| 84 | + return goodQueryAlternative(); |
| 85 | +} |
| 86 | + |
| 87 | +// Method 3: Compound Index Optimization |
| 88 | +function optimizeCompoundIndexes() { |
| 89 | + var gr = new GlideRecord('task'); |
| 90 | + |
| 91 | + // GOOD: Query fields in order that matches compound indexes |
| 92 | + // Many tables have compound indexes on (table, state, assigned_to) |
| 93 | + gr.addQuery('state', '!=', '7'); // Not closed |
| 94 | + gr.addQuery('assigned_to', '!=', ''); // Has assignee |
| 95 | + |
| 96 | + // Add additional filters after indexed ones |
| 97 | + gr.addQuery('priority', '<=', '3'); |
| 98 | + |
| 99 | + // Order by indexed field for better performance |
| 100 | + gr.orderBy('sys_updated_on'); |
| 101 | + |
| 102 | + gr.query(); |
| 103 | + |
| 104 | + return gr.getRowCount(); |
| 105 | +} |
| 106 | + |
| 107 | +// Method 4: Reference Field Optimization |
| 108 | +function optimizeReferenceQueries() { |
| 109 | + // GOOD: Query reference fields by sys_id (indexed) |
| 110 | + function queryByReferenceId() { |
| 111 | + var groupSysId = getAssignmentGroupSysId('Hardware'); |
| 112 | + |
| 113 | + var gr = new GlideRecord('incident'); |
| 114 | + gr.addQuery('assignment_group', groupSysId); // Uses index |
| 115 | + gr.addQuery('state', '!=', '7'); // Not closed |
| 116 | + gr.query(); |
| 117 | + |
| 118 | + return gr.getRowCount(); |
| 119 | + } |
| 120 | + |
| 121 | + // LESS OPTIMAL: Query by reference field display value |
| 122 | + function queryByDisplayValue() { |
| 123 | + var gr = new GlideRecord('incident'); |
| 124 | + gr.addQuery('assignment_group.name', 'Hardware'); // Less efficient |
| 125 | + gr.addQuery('state', '!=', '7'); |
| 126 | + gr.query(); |
| 127 | + |
| 128 | + return gr.getRowCount(); |
| 129 | + } |
| 130 | + |
| 131 | + // BEST: Combine both approaches |
| 132 | + function optimizedReferenceQuery() { |
| 133 | + // First get the sys_id using indexed query |
| 134 | + var groupGR = new GlideRecord('sys_user_group'); |
| 135 | + groupGR.addQuery('name', 'Hardware'); |
| 136 | + groupGR.query(); |
| 137 | + |
| 138 | + if (groupGR.next()) { |
| 139 | + var groupSysId = groupGR.getUniqueValue(); |
| 140 | + |
| 141 | + // Then use sys_id in main query (indexed) |
| 142 | + var gr = new GlideRecord('incident'); |
| 143 | + gr.addQuery('assignment_group', groupSysId); |
| 144 | + gr.addQuery('state', '!=', '7'); |
| 145 | + gr.query(); |
| 146 | + |
| 147 | + return gr.getRowCount(); |
| 148 | + } |
| 149 | + |
| 150 | + return 0; |
| 151 | + } |
| 152 | + |
| 153 | + return optimizedReferenceQuery(); |
| 154 | +} |
| 155 | + |
| 156 | +// Method 5: Date Range Optimization |
| 157 | +function optimizeDateRangeQueries() { |
| 158 | + // GOOD: Use built-in date functions with indexed timestamps |
| 159 | + function efficientDateQuery() { |
| 160 | + var gr = new GlideRecord('incident'); |
| 161 | + |
| 162 | + // Use sys_created_on (indexed) with built-in functions |
| 163 | + gr.addQuery('sys_created_on', '>=', gs.daysAgoStart(30)); |
| 164 | + gr.addQuery('sys_created_on', '<=', gs.daysAgoEnd(1)); |
| 165 | + |
| 166 | + // Add other indexed filters |
| 167 | + gr.addQuery('state', '!=', '7'); |
| 168 | + |
| 169 | + gr.query(); |
| 170 | + return gr.getRowCount(); |
| 171 | + } |
| 172 | + |
| 173 | + // LESS OPTIMAL: Complex date calculations |
| 174 | + function lessOptimalDateQuery() { |
| 175 | + var gr = new GlideRecord('incident'); |
| 176 | + |
| 177 | + // Complex date calculation (harder to optimize) |
| 178 | + var thirtyDaysAgo = new GlideDateTime(); |
| 179 | + thirtyDaysAgo.addDaysUTC(-30); |
| 180 | + |
| 181 | + gr.addQuery('sys_created_on', '>=', thirtyDaysAgo); |
| 182 | + gr.query(); |
| 183 | + |
| 184 | + return gr.getRowCount(); |
| 185 | + } |
| 186 | + |
| 187 | + return efficientDateQuery(); |
| 188 | +} |
| 189 | + |
| 190 | +// Method 6: Query Performance Analysis |
| 191 | +function analyzeQueryPerformance() { |
| 192 | + var queries = [ |
| 193 | + { |
| 194 | + name: 'Indexed Query', |
| 195 | + query: function() { |
| 196 | + var gr = new GlideRecord('incident'); |
| 197 | + gr.addQuery('state', '2'); |
| 198 | + gr.addQuery('priority', '1'); |
| 199 | + gr.setLimit(100); |
| 200 | + gr.query(); |
| 201 | + return gr.getRowCount(); |
| 202 | + } |
| 203 | + }, |
| 204 | + { |
| 205 | + name: 'Non-Indexed Query', |
| 206 | + query: function() { |
| 207 | + var gr = new GlideRecord('incident'); |
| 208 | + gr.addQuery('description', 'CONTAINS', 'test'); |
| 209 | + gr.setLimit(100); |
| 210 | + gr.query(); |
| 211 | + return gr.getRowCount(); |
| 212 | + } |
| 213 | + } |
| 214 | + ]; |
| 215 | + |
| 216 | + queries.forEach(function(queryTest) { |
| 217 | + var startTime = new Date().getTime(); |
| 218 | + var result = queryTest.query(); |
| 219 | + var endTime = new Date().getTime(); |
| 220 | + var executionTime = endTime - startTime; |
| 221 | + |
| 222 | + gs.log(queryTest.name + ':'); |
| 223 | + gs.log(' Execution time: ' + executionTime + 'ms'); |
| 224 | + gs.log(' Result count: ' + result); |
| 225 | + gs.log(' Performance rating: ' + (executionTime < 100 ? 'Good' : executionTime < 500 ? 'Fair' : 'Poor')); |
| 226 | + }); |
| 227 | +} |
| 228 | + |
| 229 | +// Helper function |
| 230 | +function getAssignmentGroupSysId(groupName) { |
| 231 | + var gr = new GlideRecord('sys_user_group'); |
| 232 | + gr.addQuery('name', groupName); |
| 233 | + gr.query(); |
| 234 | + |
| 235 | + if (gr.next()) { |
| 236 | + return gr.getUniqueValue(); |
| 237 | + } |
| 238 | + |
| 239 | + return ''; |
| 240 | +} |
| 241 | + |
| 242 | +// Method 7: Index-Aware Pagination |
| 243 | +function indexAwarePagination(pageSize, pageNumber) { |
| 244 | + pageSize = pageSize || 50; |
| 245 | + pageNumber = pageNumber || 0; |
| 246 | + |
| 247 | + var gr = new GlideRecord('incident'); |
| 248 | + |
| 249 | + // Use indexed fields for filtering |
| 250 | + gr.addQuery('state', 'IN', '1,2,3'); |
| 251 | + gr.addQuery('sys_created_on', '>=', gs.daysAgoStart(90)); |
| 252 | + |
| 253 | + // Order by indexed field for consistent pagination |
| 254 | + gr.orderBy('sys_created_on'); |
| 255 | + gr.orderByDesc('sys_id'); // Secondary sort for tie-breaking |
| 256 | + |
| 257 | + // Use chooseWindow for efficient pagination |
| 258 | + gr.chooseWindow(pageNumber * pageSize, (pageNumber + 1) * pageSize); |
| 259 | + |
| 260 | + gr.query(); |
| 261 | + |
| 262 | + var results = []; |
| 263 | + while (gr.next()) { |
| 264 | + results.push({ |
| 265 | + sys_id: gr.getUniqueValue(), |
| 266 | + number: gr.getDisplayValue('number'), |
| 267 | + short_description: gr.getDisplayValue('short_description'), |
| 268 | + state: gr.getDisplayValue('state') |
| 269 | + }); |
| 270 | + } |
| 271 | + |
| 272 | + return { |
| 273 | + data: results, |
| 274 | + page: pageNumber, |
| 275 | + pageSize: pageSize, |
| 276 | + hasMore: results.length === pageSize |
| 277 | + }; |
| 278 | +} |
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