newsupernova/vendor/magento/framework/Setup/Declaration/Schema/etc/index.xsd

<?xml version="1.0" encoding="UTF-8"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
    <xs:complexType name="index">
        <xs:annotation>
            <xs:documentation>
                Describe different SQL indexes. With help of indexes you can improve read SQL
                operations
            </xs:documentation>
        </xs:annotation>

        <xs:sequence>
            <xs:element name="column" type="indexColumnType" minOccurs="0" maxOccurs="unbounded" />
        </xs:sequence>

        <xs:attribute name="indexType" type="indexType" />
        <xs:attribute name="referenceId" type="referenceIdType" use="required" />
        <xs:attribute name="disabled" type="xs:boolean" />
    </xs:complexType>

    <xs:complexType name="indexColumnType">
        <xs:attribute name="name" type="xs:string" />
    </xs:complexType>

    <xs:simpleType name="indexType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="fulltext" />
            <xs:enumeration value="btree" />
            <xs:enumeration value="hash" />
        </xs:restriction>
    </xs:simpleType>
</xs:schema>