diff --git a/.github/workflows/coverage.yaml b/.github/workflows/coverage.yaml
index ddac502..d048782 100644
--- a/.github/workflows/coverage.yaml
+++ b/.github/workflows/coverage.yaml
@@ -19,9 +19,9 @@ jobs:
           - 6379:6379
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
       - name: Cache Cargo registry
-        uses: actions/cache@v4
+        uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
         with:
           path: ~/.cargo/registry
           key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
@@ -29,7 +29,7 @@ jobs:
             ${{ runner.os }}-cargo-registry-
 
       - name: Cache Cargo index
-        uses: actions/cache@v4
+        uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
         with:
           path: ~/.cargo/git
           key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
@@ -37,7 +37,7 @@ jobs:
             ${{ runner.os }}-cargo-index-
 
       - name: Cache Cargo build
-        uses: actions/cache@v4
+        uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
         with:
           path: target
           key: ${{ runner.os }}-cargo-build-${{ hashFiles('**/Cargo.lock') }}
@@ -46,7 +46,7 @@ jobs:
       - name: Install Rust
         run: rustup update stable
       - name: Install cargo-llvm-cov
-        uses: taiki-e/install-action@cargo-llvm-cov
+        uses: taiki-e/install-action@981088406945bfd239b6fcdeb9a73f24b463e426 # cargo-llvm-cov
       - name: Generate code coverage
         env:
           REDIS_URL: redis://localhost:6379
@@ -54,7 +54,7 @@ jobs:
           cd core
           cargo llvm-cov --all-features --workspace --lcov --output-path lcov.info
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@ab904c41d6ece82784817410c45d8b8c02684457 # v3.1.6
         with:
           token: ${{ secrets.CODECOV_TOKEN }} 
           files: core/lcov.info
diff --git a/.github/workflows/devskim.yml b/.github/workflows/devskim.yml
index 552ee1a..c730d04 100644
--- a/.github/workflows/devskim.yml
+++ b/.github/workflows/devskim.yml
@@ -18,12 +18,12 @@ jobs:
       security-events: write
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
 
       - name: Run DevSkim scanner
-        uses: microsoft/DevSkim-Action@v1
+        uses: microsoft/DevSkim-Action@914fa647b406c387000300b2f09bb28691be2b6d # v1.0.14
 
       - name: Upload DevSkim scan results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@v2
+        uses: github/codeql-action/upload-sarif@89036746af0bb9507d6f90289b0d5b97d5f44c0c # v2.26.4
         with:
           sarif_file: devskim-results.sarif
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9050101..2a12531 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -12,7 +12,6 @@ env:
 jobs:
   test:
     runs-on: ubuntu-latest
-
     services:
       redis:
         image: redis:7-alpine
@@ -21,10 +20,10 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
 
     - name: Cache Cargo registry
-      uses: actions/cache@v4
+      uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: ~/.cargo/registry
         key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
@@ -32,7 +31,7 @@ jobs:
           ${{ runner.os }}-cargo-registry-
 
     - name: Cache Cargo index
-      uses: actions/cache@v4
+      uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: ~/.cargo/git
         key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
@@ -40,14 +39,14 @@ jobs:
           ${{ runner.os }}-cargo-index-
 
     - name: Cache Cargo build
-      uses: actions/cache@v4
+      uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: target
         key: ${{ runner.os }}-cargo-build-${{ hashFiles('**/Cargo.lock') }}
         restore-keys: |
           ${{ runner.os }}-cargo-build-
     - name: Install latest nightly
-      uses: actions-rs/toolchain@v1
+      uses: actions-rs/toolchain@16499b5e05bf2e26879000db0c1d13f7e13fa3af # v1.0.7
       with:
           toolchain: nightly
           override: true
@@ -64,7 +63,7 @@ jobs:
         ls
 
     - name: Publish Test Results
-      uses: EnricoMi/publish-unit-test-result-action@v2
+      uses: EnricoMi/publish-unit-test-result-action@567cc7f8dcea3eba5da355f6ebc95663310d8a07 # v2.17.0
       with:
         files: |
           test-results/evaluation-0.xml
@@ -87,10 +86,10 @@ jobs:
     
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
 
     - name: Cache Cargo registry
-      uses: actions/cache@v4
+      uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: ~/.cargo/registry
         key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
@@ -98,7 +97,7 @@ jobs:
           ${{ runner.os }}-cargo-registry-
 
     - name: Cache Cargo index
-      uses: actions/cache@v4
+      uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: ~/.cargo/git
         key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
@@ -106,7 +105,7 @@ jobs:
           ${{ runner.os }}-cargo-index-
 
     - name: Cache Cargo build
-      uses: actions/cache@v4
+      uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4.0.2
       with:
         path: target
         key: ${{ runner.os }}-cargo-build-${{ hashFiles('**/Cargo.lock') }}
diff --git a/index-rocksdb/src/lib.rs b/index-rocksdb/src/lib.rs
index 6db69b7..7413d02 100644
--- a/index-rocksdb/src/lib.rs
+++ b/index-rocksdb/src/lib.rs
@@ -2,4 +2,3 @@ pub mod element_index;
 pub mod future_queue;
 pub mod result_index;
 mod storage_models;
-