# BasicIndex # Class: BasicIndex\ Defined in: [packages/db/src/indexes/basic-index.ts:39](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L39) Basic index using Map + sorted Array. - Map for O(1) equality lookups - Sorted Array for O(log n) range queries via binary search - O(n) updates to maintain sort order Simpler and smaller than BTreeIndex, good for read-heavy workloads. Use BTreeIndex for write-heavy workloads with large collections. ## Extends - [`BaseIndex`](BaseIndex.md)\<`TKey`\> ## Type Parameters ### TKey `TKey` *extends* `string` \| `number` = `string` \| `number` ## Constructors ### Constructor ```ts new BasicIndex( id, expression, name?, options?): BasicIndex; ``` Defined in: [packages/db/src/indexes/basic-index.ts:60](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L60) #### Parameters ##### id `number` ##### expression [`BasicExpression`](../@tanstack/namespaces/IR/type-aliases/BasicExpression.md) ##### name? `string` ##### options? `any` #### Returns `BasicIndex`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`constructor`](BaseIndex.md#constructor) ## Properties ### compareOptions ```ts protected compareOptions: CompareOptions; ``` Defined in: [packages/db/src/indexes/base-index.ts:101](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L101) #### Inherited from [`BaseIndex`](BaseIndex.md).[`compareOptions`](BaseIndex.md#compareoptions) *** ### expression ```ts readonly expression: BasicExpression; ``` Defined in: [packages/db/src/indexes/base-index.ts:95](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L95) #### Inherited from [`BaseIndex`](BaseIndex.md).[`expression`](BaseIndex.md#expression) *** ### hasCustomComparator ```ts protected hasCustomComparator: boolean = false; ``` Defined in: [packages/db/src/indexes/base-index.ts:106](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L106) Set by subclasses when constructed with a user-supplied comparator, whose ordering may not match the WHERE evaluator's relational operators. #### Inherited from [`BaseIndex`](BaseIndex.md).[`hasCustomComparator`](BaseIndex.md#hascustomcomparator) *** ### id ```ts readonly id: number; ``` Defined in: [packages/db/src/indexes/base-index.ts:93](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L93) #### Inherited from [`BaseIndex`](BaseIndex.md).[`id`](BaseIndex.md#id) *** ### lastUpdated ```ts protected lastUpdated: Date; ``` Defined in: [packages/db/src/indexes/base-index.ts:100](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L100) #### Inherited from [`BaseIndex`](BaseIndex.md).[`lastUpdated`](BaseIndex.md#lastupdated) *** ### lookupCount ```ts protected lookupCount: number = 0; ``` Defined in: [packages/db/src/indexes/base-index.ts:98](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L98) #### Inherited from [`BaseIndex`](BaseIndex.md).[`lookupCount`](BaseIndex.md#lookupcount) *** ### name? ```ts readonly optional name: string; ``` Defined in: [packages/db/src/indexes/base-index.ts:94](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L94) #### Inherited from [`BaseIndex`](BaseIndex.md).[`name`](BaseIndex.md#name) *** ### supportedOperations ```ts readonly supportedOperations: Set<"eq" | "gt" | "gte" | "lt" | "lte" | "in" | "like" | "ilike">; ``` Defined in: [packages/db/src/indexes/basic-index.ts:42](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L42) #### Overrides [`BaseIndex`](BaseIndex.md).[`supportedOperations`](BaseIndex.md#supportedoperations) *** ### totalLookupTime ```ts protected totalLookupTime: number = 0; ``` Defined in: [packages/db/src/indexes/base-index.ts:99](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L99) #### Inherited from [`BaseIndex`](BaseIndex.md).[`totalLookupTime`](BaseIndex.md#totallookuptime) ## Accessors ### indexedKeysSet #### Get Signature ```ts get indexedKeysSet(): Set; ``` Defined in: [packages/db/src/indexes/basic-index.ts:485](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L485) ##### Returns `Set`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`indexedKeysSet`](BaseIndex.md#indexedkeysset) *** ### keyCount #### Get Signature ```ts get keyCount(): number; ``` Defined in: [packages/db/src/indexes/basic-index.ts:239](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L239) Gets the number of indexed keys ##### Returns `number` #### Overrides [`BaseIndex`](BaseIndex.md).[`keyCount`](BaseIndex.md#keycount) *** ### orderedEntriesArray #### Get Signature ```ts get orderedEntriesArray(): [any, Set][]; ``` Defined in: [packages/db/src/indexes/basic-index.ts:489](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L489) ##### Returns \[`any`, `Set`\<`TKey`\>\][] #### Overrides [`BaseIndex`](BaseIndex.md).[`orderedEntriesArray`](BaseIndex.md#orderedentriesarray) *** ### orderedEntriesArrayReversed #### Get Signature ```ts get orderedEntriesArrayReversed(): [any, Set][]; ``` Defined in: [packages/db/src/indexes/basic-index.ts:496](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L496) ##### Returns \[`any`, `Set`\<`TKey`\>\][] #### Overrides [`BaseIndex`](BaseIndex.md).[`orderedEntriesArrayReversed`](BaseIndex.md#orderedentriesarrayreversed) *** ### supportsRangeOptimization #### Get Signature ```ts get supportsRangeOptimization(): boolean; ``` Defined in: [packages/db/src/indexes/base-index.ts:161](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L161) Whether range lookups (gt/gte/lt/lte) on this index can be trusted to return every matching key. Range traversal relies on the index ordering, so it is unsafe when the index uses a custom comparator, whose order may not match the WHERE evaluator's relational operators. Callers must fall back to a full scan when this is `false`. ##### Returns `boolean` #### Inherited from [`BaseIndex`](BaseIndex.md).[`supportsRangeOptimization`](BaseIndex.md#supportsrangeoptimization) *** ### valueMapData #### Get Signature ```ts get valueMapData(): Map>; ``` Defined in: [packages/db/src/indexes/basic-index.ts:505](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L505) ##### Returns `Map`\<`any`, `Set`\<`TKey`\>\> #### Overrides [`BaseIndex`](BaseIndex.md).[`valueMapData`](BaseIndex.md#valuemapdata) ## Methods ### add() ```ts add(key, item): void; ``` Defined in: [packages/db/src/indexes/basic-index.ts:79](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L79) Adds a value to the index #### Parameters ##### key `TKey` ##### item `any` #### Returns `void` #### Overrides [`BaseIndex`](BaseIndex.md).[`add`](BaseIndex.md#add) *** ### build() ```ts build(entries): void; ``` Defined in: [packages/db/src/indexes/basic-index.ts:157](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L157) Builds the index from a collection of entries #### Parameters ##### entries `Iterable`\<\[`TKey`, `any`\]\> #### Returns `void` #### Overrides [`BaseIndex`](BaseIndex.md).[`build`](BaseIndex.md#build) *** ### clear() ```ts clear(): void; ``` Defined in: [packages/db/src/indexes/basic-index.ts:194](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L194) Clears all data from the index #### Returns `void` #### Overrides [`BaseIndex`](BaseIndex.md).[`clear`](BaseIndex.md#clear) *** ### equalityLookup() ```ts equalityLookup(value): Set; ``` Defined in: [packages/db/src/indexes/basic-index.ts:246](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L246) Performs an equality lookup - O(1) #### Parameters ##### value `any` #### Returns `Set`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`equalityLookup`](BaseIndex.md#equalitylookup) *** ### evaluateIndexExpression() ```ts protected evaluateIndexExpression(item): any; ``` Defined in: [packages/db/src/indexes/base-index.ts:212](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L212) #### Parameters ##### item `any` #### Returns `any` #### Inherited from [`BaseIndex`](BaseIndex.md).[`evaluateIndexExpression`](BaseIndex.md#evaluateindexexpression) *** ### getStats() ```ts getStats(): IndexStats; ``` Defined in: [packages/db/src/indexes/base-index.ts:200](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L200) #### Returns [`IndexStats`](../interfaces/IndexStats.md) #### Inherited from [`BaseIndex`](BaseIndex.md).[`getStats`](BaseIndex.md#getstats) *** ### inArrayLookup() ```ts inArrayLookup(values): Set; ``` Defined in: [packages/db/src/indexes/basic-index.ts:470](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L470) Performs an IN array lookup - O(k) where k is values.length #### Parameters ##### values `any`[] #### Returns `Set`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`inArrayLookup`](BaseIndex.md#inarraylookup) *** ### initialize() ```ts protected initialize(_options?): void; ``` Defined in: [packages/db/src/indexes/basic-index.ts:74](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L74) #### Parameters ##### \_options? [`BasicIndexOptions`](../interfaces/BasicIndexOptions.md) #### Returns `void` #### Overrides [`BaseIndex`](BaseIndex.md).[`initialize`](BaseIndex.md#initialize) *** ### lookup() ```ts lookup(operation, value): Set; ``` Defined in: [packages/db/src/indexes/basic-index.ts:204](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L204) Performs a lookup operation #### Parameters ##### operation `"eq"` | `"gt"` | `"gte"` | `"lt"` | `"lte"` | `"in"` | `"like"` | `"ilike"` ##### value `any` #### Returns `Set`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`lookup`](BaseIndex.md#lookup) *** ### matchesCompareOptions() ```ts matchesCompareOptions(compareOptions): boolean; ``` Defined in: [packages/db/src/indexes/base-index.ts:177](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L177) Checks if the compare options match the index's compare options. The direction is ignored because the index can be reversed if the direction is different. #### Parameters ##### compareOptions `CompareOptions` #### Returns `boolean` #### Inherited from [`BaseIndex`](BaseIndex.md).[`matchesCompareOptions`](BaseIndex.md#matchescompareoptions) *** ### matchesDirection() ```ts matchesDirection(direction): boolean; ``` Defined in: [packages/db/src/indexes/base-index.ts:196](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L196) Checks if the index matches the provided direction. #### Parameters ##### direction [`OrderByDirection`](../@tanstack/namespaces/IR/type-aliases/OrderByDirection.md) #### Returns `boolean` #### Inherited from [`BaseIndex`](BaseIndex.md).[`matchesDirection`](BaseIndex.md#matchesdirection) *** ### matchesField() ```ts matchesField(fieldPath): boolean; ``` Defined in: [packages/db/src/indexes/base-index.ts:165](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L165) #### Parameters ##### fieldPath `string`[] #### Returns `boolean` #### Inherited from [`BaseIndex`](BaseIndex.md).[`matchesField`](BaseIndex.md#matchesfield) *** ### rangeQuery() ```ts rangeQuery(options): Set; ``` Defined in: [packages/db/src/indexes/basic-index.ts:254](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L254) Performs a range query using binary search - O(log n + m) #### Parameters ##### options [`RangeQueryOptions`](../interfaces/RangeQueryOptions.md) = `{}` #### Returns `Set`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`rangeQuery`](BaseIndex.md#rangequery) *** ### rangeQueryReversed() ```ts rangeQueryReversed(options): Set; ``` Defined in: [packages/db/src/indexes/basic-index.ts:315](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L315) Performs a reversed range query #### Parameters ##### options [`RangeQueryOptions`](../interfaces/RangeQueryOptions.md) = `{}` #### Returns `Set`\<`TKey`\> #### Overrides [`BaseIndex`](BaseIndex.md).[`rangeQueryReversed`](BaseIndex.md#rangequeryreversed) *** ### remove() ```ts remove(key, item): void; ``` Defined in: [packages/db/src/indexes/basic-index.ts:115](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L115) Removes a value from the index #### Parameters ##### key `TKey` ##### item `any` #### Returns `void` #### Overrides [`BaseIndex`](BaseIndex.md).[`remove`](BaseIndex.md#remove) *** ### supports() ```ts supports(operation): boolean; ``` Defined in: [packages/db/src/indexes/base-index.ts:157](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L157) #### Parameters ##### operation `"eq"` | `"gt"` | `"gte"` | `"lt"` | `"lte"` | `"in"` | `"like"` | `"ilike"` #### Returns `boolean` #### Inherited from [`BaseIndex`](BaseIndex.md).[`supports`](BaseIndex.md#supports) *** ### take() ```ts take( n, from?, filterFn?): TKey[]; ``` Defined in: [packages/db/src/indexes/basic-index.ts:340](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L340) Returns the next n items in sorted order #### Parameters ##### n `number` ##### from? `any` ##### filterFn? (`key`) => `boolean` #### Returns `TKey`[] #### Overrides [`BaseIndex`](BaseIndex.md).[`take`](BaseIndex.md#take) *** ### takeFromStart() ```ts takeFromStart(n, filterFn?): TKey[]; ``` Defined in: [packages/db/src/indexes/basic-index.ts:425](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L425) Returns the first n items in sorted order (from the start) #### Parameters ##### n `number` ##### filterFn? (`key`) => `boolean` #### Returns `TKey`[] #### Overrides [`BaseIndex`](BaseIndex.md).[`takeFromStart`](BaseIndex.md#takefromstart) *** ### takeReversed() ```ts takeReversed( n, from?, filterFn?): TKey[]; ``` Defined in: [packages/db/src/indexes/basic-index.ts:382](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L382) Returns the next n items in reverse sorted order #### Parameters ##### n `number` ##### from? `any` ##### filterFn? (`key`) => `boolean` #### Returns `TKey`[] #### Overrides [`BaseIndex`](BaseIndex.md).[`takeReversed`](BaseIndex.md#takereversed) *** ### takeReversedFromEnd() ```ts takeReversedFromEnd(n, filterFn?): TKey[]; ``` Defined in: [packages/db/src/indexes/basic-index.ts:444](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L444) Returns the first n items in reverse sorted order (from the end) #### Parameters ##### n `number` ##### filterFn? (`key`) => `boolean` #### Returns `TKey`[] #### Overrides [`BaseIndex`](BaseIndex.md).[`takeReversedFromEnd`](BaseIndex.md#takereversedfromend) *** ### trackLookup() ```ts protected trackLookup(startTime): void; ``` Defined in: [packages/db/src/indexes/base-index.ts:217](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L217) #### Parameters ##### startTime `number` #### Returns `void` #### Inherited from [`BaseIndex`](BaseIndex.md).[`trackLookup`](BaseIndex.md#tracklookup) *** ### update() ```ts update( key, oldItem, newItem): void; ``` Defined in: [packages/db/src/indexes/basic-index.ts:149](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/basic-index.ts#L149) Updates a value in the index #### Parameters ##### key `TKey` ##### oldItem `any` ##### newItem `any` #### Returns `void` #### Overrides [`BaseIndex`](BaseIndex.md).[`update`](BaseIndex.md#update) *** ### updateTimestamp() ```ts protected updateTimestamp(): void; ``` Defined in: [packages/db/src/indexes/base-index.ts:223](https://github.com/TanStack/db/blob/main/packages/db/src/indexes/base-index.ts#L223) #### Returns `void` #### Inherited from [`BaseIndex`](BaseIndex.md).[`updateTimestamp`](BaseIndex.md#updatetimestamp)