diff --git a/src/db/SQLJSPackageDB.ts b/src/db/SQLJSPackageDB.ts
index 73f6ca4..58c64c3 100644
--- a/src/db/SQLJSPackageDB.ts
+++ b/src/db/SQLJSPackageDB.ts
@@ -277,6 +277,9 @@ export class SQLJSPackageDB implements PackageDB {
       if (result.sdCharacteristics) {
         result.sdCharacteristics = JSON.parse(result.sdCharacteristics);
       }
+      if (result.sdAbstract != null) {
+        result.sdAbstract = result.sdAbstract ? true : false;
+      }
       results.push(result as ResourceInfo);
     }
     stmt.free();
diff --git a/test/db/SQLJSPackageDB.test.ts b/test/db/SQLJSPackageDB.test.ts
new file mode 100644
index 0000000..e9fa39e
--- /dev/null
+++ b/test/db/SQLJSPackageDB.test.ts
@@ -0,0 +1,591 @@
+import initSqlJs from 'sql.js';
+import { SQLJSPackageDB } from '../../src/db/SQLJSPackageDB';
+import { loggerSpy } from '../testhelpers';
+import { ResourceInfo } from '../../src/package';
+
+describe('SQLJSPackageDB', () => {
+  let SQL: initSqlJs.SqlJsStatic;
+  let sqlDb: initSqlJs.Database;
+  let dbRunSpy: jest.SpyInstance;
+
+  beforeAll(async () => {
+    SQL = await initSqlJs();
+  });
+
+  beforeEach(() => {
+    loggerSpy.reset();
+    sqlDb = new SQL.Database();
+    dbRunSpy = jest.spyOn(sqlDb, 'run');
+  });
+
+  afterEach(() => {
+    dbRunSpy.mockReset();
+    sqlDb.close();
+  });
+
+  describe('constructor', () => {
+    it('should create and initialize a new SQLJSPackageDB', () => {
+      const packageDb = new SQLJSPackageDB(sqlDb);
+      expect(packageDb).toBeDefined();
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  describe('#clear', () => {
+    let packageDb: SQLJSPackageDB;
+    const specialExtension: ResourceInfo = {
+      resourceType: 'StructureDefinition',
+      id: 'a-special-extension',
+      name: 'SpecialExtension',
+      url: 'http://example.org/Extensions/a-special-extension',
+      sdFlavor: 'Extension',
+      packageName: 'CookiePackage',
+      packageVersion: '4.5.6'
+    };
+    const valueSetThree: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'CookiePackage',
+      packageVersion: '3.2.2'
+    };
+    const valueSetFour: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'CookiePackage',
+      packageVersion: '4.5.6'
+    };
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '3.2.2',
+        packagePath: '/var/data/.fhir/CookiePackage-3.2.2'
+      });
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '4.5.6',
+        packagePath: '/var/data/.fhir/CookiePackage-4.5.6'
+      });
+      packageDb.saveResourceInfo(specialExtension);
+      packageDb.saveResourceInfo(valueSetThree);
+      packageDb.saveResourceInfo(valueSetFour);
+    });
+
+    it('should remove all packages and resources', () => {
+      // we start with some packages and resources
+      const beforePackageInfo = packageDb.findPackageInfos('CookiePackage');
+      expect(beforePackageInfo).toHaveLength(2);
+      const beforeResourceInfo = packageDb.findResourceInfos('*');
+      expect(beforeResourceInfo).toHaveLength(3);
+      // but after clear, they're gone
+      packageDb.clear();
+      const afterPackageInfo = packageDb.findPackageInfos('CookiePackage');
+      expect(afterPackageInfo).toHaveLength(0);
+      const afterResourceInfo = packageDb.findResourceInfos('*');
+      expect(afterResourceInfo).toHaveLength(0);
+    });
+  });
+
+  describe('#savePackageInfo', () => {
+    let packageDb: SQLJSPackageDB;
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+    });
+
+    it('should save package info with a name and version', () => {
+      packageDb.savePackageInfo({
+        name: 'MyPackage',
+        version: '1.0.4'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const savedPackage = packageDb.findPackageInfo('MyPackage', '1.0.4');
+      expect(savedPackage).toEqual(
+        expect.objectContaining({
+          name: 'MyPackage',
+          version: '1.0.4'
+        })
+      );
+    });
+
+    it('should save package info with a name, version, and package path', () => {
+      packageDb.savePackageInfo({
+        name: 'MyPackage',
+        version: '1.0.4',
+        packagePath: '/var/data/.fhir/MyPackage-1.0.4'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const savedPackage = packageDb.findPackageInfo('MyPackage', '1.0.4');
+      expect(savedPackage).toEqual(
+        expect.objectContaining({
+          name: 'MyPackage',
+          version: '1.0.4',
+          packagePath: '/var/data/.fhir/MyPackage-1.0.4'
+        })
+      );
+    });
+
+    it('should save package info with a name, version, and package.json path', () => {
+      packageDb.savePackageInfo({
+        name: 'MyPackage',
+        version: '1.0.4',
+        packageJSONPath: '/var/data/.fhir/MyPackage-1.0.4/package.json'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const savedPackage = packageDb.findPackageInfo('MyPackage', '1.0.4');
+      expect(savedPackage).toEqual(
+        expect.objectContaining({
+          name: 'MyPackage',
+          version: '1.0.4',
+          packageJSONPath: '/var/data/.fhir/MyPackage-1.0.4/package.json'
+        })
+      );
+    });
+
+    it('should save package info with a name, version, package path, and package.json path', () => {
+      packageDb.savePackageInfo({
+        name: 'MyPackage',
+        version: '1.0.4',
+        packagePath: '/var/data/.fhir/MyPackage-1.0.4',
+        packageJSONPath: '/var/data/.fhir/MyPackage-1.0.4/package.json'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const savedPackage = packageDb.findPackageInfo('MyPackage', '1.0.4');
+      expect(savedPackage).toEqual(
+        expect.objectContaining({
+          name: 'MyPackage',
+          version: '1.0.4',
+          packagePath: '/var/data/.fhir/MyPackage-1.0.4',
+          packageJSONPath: '/var/data/.fhir/MyPackage-1.0.4/package.json'
+        })
+      );
+    });
+  });
+
+  describe('#saveResourceInfo', () => {
+    let packageDb: SQLJSPackageDB;
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+    });
+
+    it('should save a simple resource', () => {
+      packageDb.saveResourceInfo({
+        resourceType: 'StructureDefinition',
+        id: 'my-patient-profile'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const resource = packageDb.findResourceInfo('my-patient-profile');
+      expect(resource).toEqual(
+        expect.objectContaining({
+          resourceType: 'StructureDefinition',
+          id: 'my-patient-profile'
+        })
+      );
+    });
+
+    it('should save a resource with additional information', () => {
+      packageDb.saveResourceInfo({
+        resourceType: 'ValueSet',
+        id: 'my-value-set',
+        url: 'http://example.org/ValueSets/my-value-set',
+        name: 'MyValueSet',
+        version: '3.1.3',
+        packageName: 'RegularPackage',
+        packageVersion: '3.2.2',
+        resourcePath: '/var/data/.fhir/RegularPackage-3.2.2/ValueSets/my-value-set.json'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const resource = packageDb.findResourceInfo('my-value-set');
+      expect(resource).toEqual(
+        expect.objectContaining({
+          resourceType: 'ValueSet',
+          id: 'my-value-set',
+          url: 'http://example.org/ValueSets/my-value-set',
+          name: 'MyValueSet',
+          version: '3.1.3',
+          packageName: 'RegularPackage',
+          packageVersion: '3.2.2',
+          resourcePath: '/var/data/.fhir/RegularPackage-3.2.2/ValueSets/my-value-set.json'
+        })
+      );
+    });
+
+    it('should save a resource with additional structure definition information', () => {
+      packageDb.saveResourceInfo({
+        resourceType: 'StructureDefinition',
+        id: 'my-patient-profile',
+        name: 'MyPatientProfile',
+        sdKind: 'resource',
+        sdDerivation: 'constraint',
+        sdType: 'Patient',
+        sdBaseDefinition: 'http://hl7.org/fhir/StructureDefinition/Patient',
+        sdAbstract: false,
+        sdImposeProfiles: [
+          'http://example.org/SomeOtherPatient',
+          'http://example.org/YetAnotherPatient'
+        ],
+        // a profile wouldn't normally have characteristics,
+        // but they are used here for test purposes
+        sdCharacteristics: ['can-be-target', 'do-translations'],
+        sdFlavor: 'Profile',
+        packageName: 'RegularPackage',
+        packageVersion: '3.2.2'
+      });
+      expect(dbRunSpy).toHaveBeenCalledTimes(1);
+      const resource = packageDb.findResourceInfo('my-patient-profile');
+      expect(resource).toEqual(
+        expect.objectContaining({
+          resourceType: 'StructureDefinition',
+          id: 'my-patient-profile',
+          name: 'MyPatientProfile',
+          sdKind: 'resource',
+          sdDerivation: 'constraint',
+          sdType: 'Patient',
+          sdBaseDefinition: 'http://hl7.org/fhir/StructureDefinition/Patient',
+          sdAbstract: false,
+          sdImposeProfiles: [
+            'http://example.org/SomeOtherPatient',
+            'http://example.org/YetAnotherPatient'
+          ],
+          sdCharacteristics: ['can-be-target', 'do-translations'],
+          sdFlavor: 'Profile',
+          packageName: 'RegularPackage',
+          packageVersion: '3.2.2'
+        })
+      );
+    });
+  });
+
+  describe('#findPackageInfos', () => {
+    let packageDb: SQLJSPackageDB;
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '1.0.0',
+        packagePath: '/var/data/.fhir/CookiePackage-1.0.0'
+      });
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '1.0.3',
+        packagePath: '/var/data/.fhir/CookiePackage-1.0.3'
+      });
+      packageDb.savePackageInfo({
+        name: 'BagelPackage',
+        version: '1.0.0',
+        packagePath: '/var/data/.fhir/BagelPackage-1.0.0'
+      });
+    });
+
+    it('should return all packages that match a name', () => {
+      const results = packageDb.findPackageInfos('CookiePackage');
+      expect(results).toHaveLength(2);
+      expect(results).toContainEqual(
+        expect.objectContaining({
+          name: 'CookiePackage',
+          version: '1.0.0',
+          packagePath: '/var/data/.fhir/CookiePackage-1.0.0'
+        })
+      );
+      expect(results).toContainEqual(
+        expect.objectContaining({
+          name: 'CookiePackage',
+          version: '1.0.3',
+          packagePath: '/var/data/.fhir/CookiePackage-1.0.3'
+        })
+      );
+    });
+
+    it('should return an empty list when no packages match a name', () => {
+      const results = packageDb.findPackageInfos('MysteryPackage');
+      expect(results).toHaveLength(0);
+    });
+  });
+
+  describe('#findPackageInfo', () => {
+    let packageDb: SQLJSPackageDB;
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '1.0.0',
+        packagePath: '/var/data/.fhir/CookiePackage-1.0.0'
+      });
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '1.0.3',
+        packagePath: '/var/data/.fhir/CookiePackage-1.0.3'
+      });
+      packageDb.savePackageInfo({
+        name: 'BagelPackage',
+        version: '1.0.0',
+        packagePath: '/var/data/.fhir/BagelPackage-1.0.0'
+      });
+    });
+
+    it('should return a package that matches a name and version', () => {
+      const result = packageDb.findPackageInfo('CookiePackage', '1.0.3');
+      expect(result).toEqual(
+        expect.objectContaining({
+          name: 'CookiePackage',
+          version: '1.0.3',
+          packagePath: '/var/data/.fhir/CookiePackage-1.0.3'
+        })
+      );
+    });
+
+    it('should return undefined when no package matches the name and version', () => {
+      const wrongVersion = packageDb.findPackageInfo('BagelPackage', '1.0.2');
+      expect(wrongVersion).toBeUndefined();
+      const wrongName = packageDb.findPackageInfo('MysteryPackage', '1.0.0');
+      expect(wrongName).toBeUndefined();
+    });
+  });
+
+  describe('#findResourceInfos', () => {
+    let packageDb: SQLJSPackageDB;
+    const patientProfile: ResourceInfo = {
+      resourceType: 'StructureDefinition',
+      id: 'my-patient-profile',
+      name: 'MyPatientProfile',
+      sdKind: 'resource',
+      sdDerivation: 'constraint',
+      sdType: 'Patient',
+      sdBaseDefinition: 'http://hl7.org/fhir/StructureDefinition/Patient',
+      sdFlavor: 'Profile',
+      packageName: 'RegularPackage',
+      packageVersion: '3.2.2'
+    };
+    const observationProfile: ResourceInfo = {
+      resourceType: 'StructureDefinition',
+      id: 'my-observation-profile',
+      name: 'MyObservationProfile',
+      sdKind: 'resource',
+      sdFlavor: 'Profile',
+      packageName: 'SecretPackage',
+      packageVersion: '3.2.2'
+    };
+    const specialExtension: ResourceInfo = {
+      resourceType: 'StructureDefinition',
+      id: 'a-special-extension',
+      name: 'SpecialExtension',
+      url: 'http://example.org/Extensions/a-special-extension',
+      sdFlavor: 'Extension',
+      packageName: 'RegularPackage',
+      packageVersion: '4.5.6'
+    };
+    const valueSetThree: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'RegularPackage',
+      packageVersion: '3.2.2'
+    };
+    const valueSetFour: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'RegularPackage',
+      packageVersion: '4.5.6'
+    };
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+      packageDb.saveResourceInfo(patientProfile);
+      packageDb.saveResourceInfo(observationProfile);
+      packageDb.saveResourceInfo(specialExtension);
+      packageDb.saveResourceInfo(valueSetThree);
+      packageDb.saveResourceInfo(valueSetFour);
+    });
+
+    it('should find all resources when the key is *', () => {
+      const resources = packageDb.findResourceInfos('*');
+      expect(resources).toHaveLength(5);
+      expect(resources).toContainEqual(expect.objectContaining(patientProfile));
+      expect(resources).toContainEqual(expect.objectContaining(observationProfile));
+      expect(resources).toContainEqual(expect.objectContaining(specialExtension));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetThree));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetFour));
+    });
+
+    it('should find resources where the key matches the resource id', () => {
+      const resources = packageDb.findResourceInfos('my-observation-profile');
+      expect(resources).toHaveLength(1);
+      expect(resources).toContainEqual(expect.objectContaining(observationProfile));
+    });
+
+    it('should find resources where the key matches the resource name', () => {
+      const resources = packageDb.findResourceInfos('SpecialExtension');
+      expect(resources).toHaveLength(1);
+      expect(resources).toContainEqual(expect.objectContaining(specialExtension));
+    });
+
+    it('should find resources where the key matches the resource url', () => {
+      const resources = packageDb.findResourceInfos('http://example.org/ValueSets/my-value-set');
+      expect(resources).toHaveLength(2);
+      expect(resources).toContainEqual(expect.objectContaining(valueSetThree));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetFour));
+    });
+
+    it('should find resources that match a package name', () => {
+      const resources = packageDb.findResourceInfos('*', {
+        scope: 'RegularPackage'
+      });
+      expect(resources).toHaveLength(4);
+      expect(resources).toContainEqual(expect.objectContaining(patientProfile));
+      expect(resources).toContainEqual(expect.objectContaining(specialExtension));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetThree));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetFour));
+    });
+
+    it('should find resources that match a package name and package version', () => {
+      const resources = packageDb.findResourceInfos('*', {
+        scope: 'RegularPackage|3.2.2'
+      });
+      expect(resources).toHaveLength(2);
+      expect(resources).toContainEqual(expect.objectContaining(patientProfile));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetThree));
+    });
+
+    it('should find resources that match one of the provided types', () => {
+      const resources = packageDb.findResourceInfos('*', {
+        type: ['Extension', 'ValueSet']
+      });
+      expect(resources).toHaveLength(3);
+      expect(resources).toContainEqual(expect.objectContaining(specialExtension));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetThree));
+      expect(resources).toContainEqual(expect.objectContaining(valueSetFour));
+    });
+
+    it('should limit the number of results based on the limit option', () => {
+      const resources = packageDb.findResourceInfos('*', {
+        limit: 2
+      });
+      expect(resources).toHaveLength(2);
+    });
+  });
+
+  describe('#findResourceInfo', () => {
+    let packageDb: SQLJSPackageDB;
+    const specialExtension: ResourceInfo = {
+      resourceType: 'StructureDefinition',
+      id: 'a-special-extension',
+      name: 'SpecialExtension',
+      url: 'http://example.org/Extensions/a-special-extension',
+      sdFlavor: 'Extension',
+      packageName: 'RegularPackage',
+      packageVersion: '4.5.6'
+    };
+    const valueSetThree: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'RegularPackage',
+      packageVersion: '3.2.2'
+    };
+    const valueSetFour: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'RegularPackage',
+      packageVersion: '4.5.6'
+    };
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+      packageDb.saveResourceInfo(specialExtension);
+      packageDb.saveResourceInfo(valueSetThree);
+      packageDb.saveResourceInfo(valueSetFour);
+    });
+
+    it('should return one resource when there is at least one match', () => {
+      const resource = packageDb.findResourceInfo('my-value-set');
+      expect(resource).toBeDefined();
+      // both valueSetThree and valueSetFour have a matching id,
+      // but the last resource added wins.
+      expect(resource).toEqual(expect.objectContaining(valueSetFour));
+    });
+
+    it('should return undefined when there are no matches', () => {
+      const resource = packageDb.findResourceInfo('nonexistent-profile');
+      expect(resource).toBeUndefined();
+    });
+  });
+
+  describe('#getPackageStats', () => {
+    let packageDb: SQLJSPackageDB;
+    const specialExtension: ResourceInfo = {
+      resourceType: 'StructureDefinition',
+      id: 'a-special-extension',
+      name: 'SpecialExtension',
+      url: 'http://example.org/Extensions/a-special-extension',
+      sdFlavor: 'Extension',
+      packageName: 'CookiePackage',
+      packageVersion: '4.5.6'
+    };
+    const valueSetThree: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'CookiePackage',
+      packageVersion: '3.2.2'
+    };
+    const valueSetFour: ResourceInfo = {
+      resourceType: 'ValueSet',
+      id: 'my-value-set',
+      url: 'http://example.org/ValueSets/my-value-set',
+      name: 'MyValueSet',
+      packageName: 'CookiePackage',
+      packageVersion: '4.5.6'
+    };
+
+    beforeEach(() => {
+      packageDb = new SQLJSPackageDB(sqlDb);
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '3.2.2',
+        packagePath: '/var/data/.fhir/CookiePackage-3.2.2'
+      });
+      packageDb.savePackageInfo({
+        name: 'CookiePackage',
+        version: '4.5.6',
+        packagePath: '/var/data/.fhir/CookiePackage-4.5.6'
+      });
+      packageDb.savePackageInfo({
+        name: 'BagelPackage',
+        version: '3.2.2',
+        packagePath: '/var/data/.fhir/BagelPackage-3.2.2'
+      });
+      packageDb.saveResourceInfo(specialExtension);
+      packageDb.saveResourceInfo(valueSetThree);
+      packageDb.saveResourceInfo(valueSetFour);
+    });
+
+    it('should return a count of resources for a package', () => {
+      const result = packageDb.getPackageStats('CookiePackage', '4.5.6');
+      expect(result).toEqual({
+        name: 'CookiePackage',
+        version: '4.5.6',
+        resourceCount: 2
+      });
+    });
+
+    it('should return undefined when there is no info for a package', () => {
+      const result = packageDb.getPackageStats('BagelPackage', '4.5.6');
+      expect(result).toBeUndefined();
+    });
+  });
+});